CWE-94¶
Improper Control of Generation of Code (‘Code Injection’). [Data-Neutralization-Issues, Improper-Neutralization, Top25-2024-11]
Required inputs: IR, StaticSemanticAnalysis
When a product allows a user's input to contain code syntax, it might be possible for an attacker to craft the code in such a way that it will alter the intended control flow of the product. Such an alteration could lead to arbitrary code execution.
Injection problems encompass a wide variety of issues -- all mitigated in very different ways. For this reason, the most effective way to discuss these weaknesses is to note the distinct features which classify them as injection weaknesses. The most important issue to note is that all injection problems share one thing in common -- i.e., they allow for the injection of control plane data into the user-controlled data plane. This means that the execution of the process may be altered by sending code in through legitimate data channels, using no other mechanism. While buffer overflows, and many other flaws, involve the use of some further issue to gain execution, injection problems need only for the data to be parsed. The most classic instantiations of this category of weakness are SQL injection and format string vulnerabilities.
Demonstrative Examples
Example 1
This example attempts to write user messages to a message file and allow users to view them.
Example Language:PHP (Unsupported language for documentation only)
$MessageFile = "messages.out";
if ($_GET["action"] == "NewMessage") {
$name = $_GET["name"];
$message = $_GET["message"];
$handle = fopen($MessageFile, "a+");
fwrite($handle, "<b>$name</b> says '$message'<hr>\n");
fclose($handle);
echo "Message Saved!<p>\n";
}
else if ($_GET["action"] == "ViewMessages") {
include($MessageFile);
}
While the programmer intends for the MessageFile to only include data, an attacker can provide a message such as:
(attack code)
name=h4x0r
message=%3C?php%20system(%22/bin/ls%20-l%22);?%3E
which will decode to the following:
(attack code)
<?php system("/bin/ls -l");?>
The programmer thought they were just including the contents of a regular data file, but PHP parsed it and executed the code. Now, this code is executed any time people view messages.
Notice that XSS (CWE-79) is also possible in this situation.
Example 2
edit-config.pl: This CGI script is used to modify settings in a configuration file.
Example Language:Perl (Unsupported language for documentation only)
use CGI qw(:standard);
sub config_file_add_key {
my ($fname, $key, $arg) = @_;
# code to add a field/key to a file goes here
}
sub config_file_set_key {
my ($fname, $key, $arg) = @_;
# code to set key to a particular file goes here
}
sub config_file_delete_key {
my ($fname, $key, $arg) = @_;
# code to delete key from a particular file goes here
}
sub handleConfigAction {
my ($fname, $action) = @_;
my $key = param('key');
my $val = param('val');
# this is super-efficient code, especially if you have to invoke
# any one of dozens of different functions!
my $code = "config_file_$action_key(\$fname, \$key, \$val);";
eval($code);
}
$configfile = "/home/cwe/config.txt";
print header;
if (defined(param('action'))) {
handleConfigAction($configfile, param('action'));
}
else {
print "No action specified!\n";
}
The script intends to take the 'action' parameter and invoke one of a variety of functions based on the value of that parameter - config_file_add_key(), config_file_set_key(), or config_file_delete_key(). It could set up a conditional to invoke each function separately, but eval() is a powerful way of doing the same thing in fewer lines of code, especially when a large number of functions or variables are involved. Unfortunately, in this case, the attacker can provide other values in the action parameter, such as:
(attack code)
add_key(",","); system("/bin/ls");
This would produce the following string in handleConfigAction():
(result)
config_file_add_key(",","); system("/bin/ls");
Any arbitrary Perl code could be added after the attacker has "closed off" the construction of the original function call, in order to prevent parsing errors from causing the malicious eval() to fail before the attacker's payload is activated. This particular manipulation would fail after the system() call, because the "_key(\$fname, \$key, \$val)" portion of the string would cause an error, but this is irrelevant to the attack because the payload has already been activated.
Example 3
This simple script asks a user to supply a list of numbers as input and adds them together.
Example Language:Python (Unsupported language for documentation only)
def main():
sum = 0
numbers = eval(input("Enter a space-separated list of numbers: "))
for num in numbers:
sum = sum + num
print(f"Sum of {numbers} = {sum}")
main()
The eval() function can take the user-supplied list and convert it into a Python list object, therefore allowing the programmer to use list comprehension methods to work with the data. However, if code is supplied to the eval() function, it will execute that code. For example, a malicious user could supply the following string:
(attack code)
__import__('subprocess').getoutput('rm -r *')
This would delete all the files in the current directory. For this reason, it is not recommended to use eval() with untrusted input.
A way to accomplish this without the use of eval() is to apply an integer conversion on the input within a try/except block. If the user-supplied input is not numeric, this will raise a ValueError. By avoiding eval(), there is no opportunity for the input string to be executed as code.
Example Language:Python (Unsupported language for documentation only)
def main():
sum = 0
numbers = input("Enter a space-separated list of numbers: ").split(" ")
try:
for num in numbers:
sum = sum + int(num)
print(f"Sum of {numbers} = {sum}")
except ValueError:
print("Error: invalid input")
main()
An alternative, commonly-cited mitigation for this kind of weakness is to use the ast.literal_eval() function, since it is intentionally designed to avoid executing code. However, an adversary could still cause excessive memory or stack consumption via deeply nested structures [REF-1372], so the python documentation discourages use of ast.literal_eval() on untrusted data [REF-1373].
Excerpts from CWE [https://cwe.mitre.org], Copyright (C) 2006-2026, the MITRE Corporation. See section 9.4. "3rd-Party Licenses" in the documentation for full details.Possible Messages
Key |
Text |
Severity |
Disabled |
|---|---|---|---|
unchecked_external_value |
Executing OS command without neutralization of special elements. |
None |
False |
Options¶
This rule shares the following common options: exclude_in_macros, exclude_messages_in_system_headers, excludes, extend_exclude_to_macro_invocations, includes, justification_checker, languages, post_processing, provider, report_at, severity
The following places define options that affect this rule: Stylechecks, Analysis-GlobalOptions
all_external_functions_as_sinks¶
all_external_functions_as_sinks : bool = False
all_external_functions_as_sources¶
all_external_functions_as_sources : bool = True
external_sources¶
Description of the possible sources of external values.
external_sources.arguments_of
Description of functions for which pointer arguments should be treated as an external value that must be checked after calling the function. For each function, an argument specifier needs to be set that describes a selection of argument numbers that shall be considered. A numberxis considered iff(x >= argument_range_min and x <= argument_range_max and argument_numbers_set.empty())orx in argument_numbers_set. If the table is empty, all non-const pointer parameters of external functions are checked.
external_sources.arguments_of.excluded
Functions which should be exempt from the set of functions for which the arguments should be checked before using them.Type: dict[bauhaus.analysis.config.QualifiedName, ArgumentSpecifier]
Default:
{ '__axivion_add_local_static__': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set=set(), argument_range_max=4294967295, argument_range_min=0 ), '__axivion_get_array_size__': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0}, argument_range_max=4294967295, argument_range_min=0 ), '__axivion_get_polymorphic_size__': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0}, argument_range_max=4294967295, argument_range_min=0 ), '__builtin___strcat_chk': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0, 1}, argument_range_max=4294967295, argument_range_min=0 ), '__builtin___strcpy_chk': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0, 1}, argument_range_max=4294967295, argument_range_min=0 ), '__builtin_memcpy': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0}, argument_range_max=4294967295, argument_range_min=0 ), '__sigsetjmp': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0}, argument_range_max=4294967295, argument_range_min=0 ), 'bcopy': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={1}, argument_range_max=4294967295, argument_range_min=0 ), 'confstr': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={1}, argument_range_max=4294967295, argument_range_min=0 ), 'fclose': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set=set(), argument_range_max=4294967295, argument_range_min=0 ), 'ferror': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0}, argument_range_max=4294967295, argument_range_min=0 ), 'fflush': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0}, argument_range_max=4294967295, argument_range_min=0 ), 'fgetc': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set=set(), argument_range_max=4294967295, argument_range_min=0 ), 'fileno': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0}, argument_range_max=4294967295, argument_range_min=0 ), 'fprintf': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set=set(), argument_range_max=4294967295, argument_range_min=0 ), 'free': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0}, argument_range_max=4294967295, argument_range_min=0 ), 'fstat': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={1}, argument_range_max=4294967295, argument_range_min=0 ), 'getcwd': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0}, argument_range_max=4294967295, argument_range_min=0 ), 'getgroups': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={1}, argument_range_max=4294967295, argument_range_min=0 ), 'gethostname': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0}, argument_range_max=4294967295, argument_range_min=0 ), 'getrlimit': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={1}, argument_range_max=4294967295, argument_range_min=0 ), 'getrusage': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={1}, argument_range_max=4294967295, argument_range_min=0 ), 'memcpy': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set=set(), argument_range_max=4294967295, argument_range_min=0 ), 'memmove': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0}, argument_range_max=4294967295, argument_range_min=0 ), 'memset': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set=set(), argument_range_max=4294967295, argument_range_min=0 ), 'mremap': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set=set(), argument_range_max=4294967295, argument_range_min=0 ), 'munmap': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set=set(), argument_range_max=4294967295, argument_range_min=0 ), 'operator delete': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0}, argument_range_max=4294967295, argument_range_min=0 ), 'operator delete[]': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0}, argument_range_max=4294967295, argument_range_min=0 ), 'pclose': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set=set(), argument_range_max=4294967295, argument_range_min=0 ), 'pipe': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0}, argument_range_max=4294967295, argument_range_min=0 ), 'printf': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set=set(), argument_range_max=4294967295, argument_range_min=0 ), 'pthread_mutex_destroy': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set=set(), argument_range_max=4294967295, argument_range_min=0 ), 'pthread_mutex_init': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set=set(), argument_range_max=4294967295, argument_range_min=0 ), 'pthread_mutex_lock': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set=set(), argument_range_max=4294967295, argument_range_min=0 ), 'pthread_mutex_trylock': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set=set(), argument_range_max=4294967295, argument_range_min=0 ), 'pthread_mutex_unlock': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set=set(), argument_range_max=4294967295, argument_range_min=0 ), 'pthread_mutexattr_destroy': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set=set(), argument_range_max=4294967295, argument_range_min=0 ), 'pthread_mutexattr_init': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set=set(), argument_range_max=4294967295, argument_range_min=0 ), 'pthread_mutexattr_settype': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set=set(), argument_range_max=4294967295, argument_range_min=0 ), 'putc': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={1}, argument_range_max=4294967295, argument_range_min=0 ), 'qsort': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0}, argument_range_max=4294967295, argument_range_min=0 ), 'read': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={1}, argument_range_max=4294967295, argument_range_min=0 ), 'realloc': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set=set(), argument_range_max=4294967295, argument_range_min=0 ), 'regfree': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0}, argument_range_max=4294967295, argument_range_min=0 ), 'sigaddset': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0}, argument_range_max=4294967295, argument_range_min=0 ), 'sigdelset': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0}, argument_range_max=4294967295, argument_range_min=0 ), 'sigemptyset': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0}, argument_range_max=4294967295, argument_range_min=0 ), 'sigfillset': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0}, argument_range_max=4294967295, argument_range_min=0 ), 'sprintf': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set=set(), argument_range_max=4294967295, argument_range_min=0 ), 'std::operator<<': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0}, argument_range_max=4294967295, argument_range_min=0 ), 'strcat': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0, 1}, argument_range_max=4294967295, argument_range_min=0 ), 'strcpy': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0, 1}, argument_range_max=4294967295, argument_range_min=0 ), 'strncat': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0, 1}, argument_range_max=4294967295, argument_range_min=0 ), 'strncpy': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0, 1}, argument_range_max=4294967295, argument_range_min=0 ), 'tcgetattr': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={1}, argument_range_max=4294967295, argument_range_min=0 ), 'time': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0}, argument_range_max=4294967295, argument_range_min=0 ), 'vsnprintf': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set=set(), argument_range_max=4294967295, argument_range_min=0 ), 'waitpid': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={1}, argument_range_max=4294967295, argument_range_min=0 ), 'wmemset': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set=set(), argument_range_max=4294967295, argument_range_min=0 ) }
external_sources.arguments_of.functions
Table of functions and argument specifiers where the function sets the matched arguments to an external value that must be checked before use. If the table is empty, all non-const pointer parameters of external functions are checked, except for functions listed in theType: dict[bauhaus.analysis.config.QualifiedName, ArgumentSpecifier]
Default:
{ 'fgets': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0}, argument_range_max=4294967295, argument_range_min=0 ), 'fread': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0}, argument_range_max=4294967295, argument_range_min=0 ), 'fscanf': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set=set(), argument_range_max=4294967295, argument_range_min=2 ), 'fscanf_s': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set=set(), argument_range_max=4294967295, argument_range_min=2 ), 'recv': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={1}, argument_range_max=4294967295, argument_range_min=0 ), 'scanf': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set=set(), argument_range_max=4294967295, argument_range_min=1 ), 'scanf_s': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set=set(), argument_range_max=4294967295, argument_range_min=1 ) }arguments_of.excludedoption.
external_sources.parameters_of
Functions configured as entry points (including main) for which the parameters should be checked before using them. If the set is empty, all entry points are checked.
external_sources.parameters_of.excluded : set[bauhaus.analysis.config.QualifiedName] =
Functions which should be exempt from the set of functions for which the parameters should be checked before using them.set()
external_sources.parameters_of.functions : set[bauhaus.analysis.config.QualifiedName] =
Functions configured as entry points (including main) for which the parameters should be checked before using them. If the set is empty, all entry points are checked.set()
external_sources.return_values_of
Functions for which the return value should be considered an external value that must be checked before use.
external_sources.return_values_of.excluded
Functions which should be exempt from the set of functions for which the return value should be treated as an external value.Type: set[bauhaus.analysis.config.QualifiedName]
Default:
{'__acrt_iob_func', '__builtin_alloca', '__builtin_ctz', '__builtin_ia32_pblendw128', '__builtin_ia32_pshufd', '__builtin_ia32_pshufhw', '__builtin_ia32_pshuflw', '__builtin_ia32_pslldqi128', '__builtin_ia32_psrldqi128', '__builtin_ia32_shufps', '__builtin_isinf', '__builtin_isinff', '__builtin_isnan', '__builtin_isnanf', '__ctype_b_loc', '__ctype_get_mb_cur_max', '__errno_location', '__iob_func', '__sigsetjmp', '_mm256_abs_epi16', '_mm256_abs_epi32', '_mm256_abs_epi8', '_mm256_add_epi16', '_mm256_add_epi32', '_mm256_add_epi64', '_mm256_add_epi8', '_mm256_add_pd', '_mm256_add_ps', '_mm256_adds_epi16', '_mm256_adds_epi8', '_mm256_adds_epu16', '_mm256_adds_epu8', '_mm256_alignr_epi8', '_mm256_and_pd', '_mm256_and_ps', '_mm256_and_si256', '_mm256_blend_epi32', '_mm256_blend_pd', '_mm256_blend_ps', '_mm256_blendv_epi8', '_mm256_blendv_pd', '_mm256_blendv_ps', '_mm256_broadcastsi128_si256', '_mm256_castpd128_pd256', '_mm256_castpd256_pd128', '_mm256_castpd_ps', '_mm256_castpd_si256', '_mm256_castps128_ps256', '_mm256_castps256_ps128', '_mm256_castps_pd', '_mm256_castps_si256', '_mm256_castsi128_si256', '_mm256_castsi256_pd', '_mm256_castsi256_ps', '_mm256_castsi256_si128', '_mm256_cmp_pd', '_mm256_cmp_ps', '_mm256_cmpeq_epi16', '_mm256_cmpeq_epi32', '_mm256_cmpeq_epi64', '_mm256_cmpeq_epi8', '_mm256_cmpgt_epi16', '_mm256_cmpgt_epi32', '_mm256_cmpgt_epi8', '_mm256_cvtepi16_epi32', '_mm256_cvtepi32_epi64', '_mm256_cvtepi32_pd', '_mm256_cvtepi32_ps', '_mm256_cvtepi8_epi16', '_mm256_cvtepi8_epi32', '_mm256_cvtepu16_epi32', '_mm256_cvtepu32_epi64', '_mm256_cvtepu8_epi16', '_mm256_cvtepu8_epi32', '_mm256_cvtpd_epi32', '_mm256_cvtpd_ps', '_mm256_cvtph_ps', '_mm256_cvtps_epi32', '_mm256_cvtps_pd', '_mm256_cvtps_ph', '_mm256_cvttpd_epi32', '_mm256_cvttps_epi32', '_mm256_div_pd', '_mm256_div_ps', '_mm256_extractf128_pd', '_mm256_extractf128_ps', '_mm256_extracti128_si256', '_mm256_fmadd_pd', '_mm256_fmadd_ps', '_mm256_hadd_epi32', '_mm256_hadd_ps', '_mm256_i32gather_epi32', '_mm256_i32gather_epi64', '_mm256_i32gather_pd', '_mm256_i32gather_ps', '_mm256_insertf128_pd', '_mm256_insertf128_ps', '_mm256_inserti128_si256', '_mm256_load_pd', '_mm256_load_ps', '_mm256_load_si256', '_mm256_loadu_pd', '_mm256_loadu_ps', '_mm256_loadu_si256', '_mm256_madd_epi16', '_mm256_max_epi16', '_mm256_max_epi32', '_mm256_max_epi8', '_mm256_max_epu16', '_mm256_max_epu32', '_mm256_max_epu8', '_mm256_max_pd', '_mm256_max_ps', '_mm256_min_epi16', '_mm256_min_epi32', '_mm256_min_epi8', '_mm256_min_epu16', '_mm256_min_epu32', '_mm256_min_epu8', '_mm256_min_pd', '_mm256_min_ps', '_mm256_movemask_epi8', '_mm256_movemask_pd', '_mm256_movemask_ps', '_mm256_mul_epi32', '_mm256_mul_epu32', '_mm256_mul_pd', '_mm256_mul_ps', '_mm256_mulhi_epi16', '_mm256_mulhi_epu16', '_mm256_mullo_epi16', '_mm256_mullo_epi32', '_mm256_or_pd', '_mm256_or_ps', '_mm256_or_si256', '_mm256_packs_epi32', '_mm256_packus_epi32', '_mm256_permute2f128_pd', '_mm256_permute2f128_ps', '_mm256_permute2x128_si256', '_mm256_permute4x64_epi64', '_mm256_permute4x64_pd', '_mm256_permute_ps', '_mm256_permutevar8x32_epi32', '_mm256_permutevar8x32_ps', '_mm256_round_pd', '_mm256_round_ps', '_mm256_rsqrt_ps', '_mm256_sad_epu8', '_mm256_set1_epi16', '_mm256_set1_epi32', '_mm256_set1_epi64x', '_mm256_set1_epi8', '_mm256_set1_pd', '_mm256_set1_ps', '_mm256_set_epi64x', '_mm256_setr_epi16', '_mm256_setr_epi32', '_mm256_setr_epi8', '_mm256_setzero_pd', '_mm256_setzero_ps', '_mm256_setzero_si256', '_mm256_shuffle_epi32', '_mm256_shuffle_epi8', '_mm256_shuffle_pd', '_mm256_slli_epi16', '_mm256_slli_epi32', '_mm256_slli_epi64', '_mm256_slli_si256', '_mm256_sqrt_pd', '_mm256_sqrt_ps', '_mm256_srai_epi16', '_mm256_srai_epi32', '_mm256_srli_epi16', '_mm256_srli_epi32', '_mm256_srli_epi64', '_mm256_srli_si256', '_mm256_sub_epi16', '_mm256_sub_epi32', '_mm256_sub_epi64', '_mm256_sub_epi8', '_mm256_sub_pd', '_mm256_sub_ps', '_mm256_subs_epi16', '_mm256_subs_epi8', '_mm256_subs_epu16', '_mm256_subs_epu8', '_mm256_unpackhi_epi16', '_mm256_unpackhi_epi32', '_mm256_unpackhi_epi64', '_mm256_unpackhi_epi8', '_mm256_unpackhi_pd', '_mm256_unpackhi_ps', '_mm256_unpacklo_epi16', '_mm256_unpacklo_epi32', '_mm256_unpacklo_epi64', '_mm256_unpacklo_epi8', '_mm256_unpacklo_pd', '_mm256_unpacklo_ps', '_mm256_xor_pd', '_mm256_xor_ps', '_mm256_xor_si256', '_mm_add_epi16', '_mm_add_epi32', '_mm_add_epi64', '_mm_add_epi8', '_mm_add_pd', '_mm_add_ps', '_mm_adds_epi16', '_mm_adds_epi8', '_mm_adds_epu16', '_mm_adds_epu8', '_mm_addsub_ps', '_mm_and_pd', '_mm_and_ps', '_mm_and_si128', '_mm_andnot_si128', '_mm_blend_epi16', '_mm_blendv_epi8', '_mm_blendv_pd', '_mm_blendv_ps', '_mm_castpd_ps', '_mm_castpd_si128', '_mm_castps_pd', '_mm_castps_si128', '_mm_castsi128_pd', '_mm_castsi128_ps', '_mm_cmpeq_epi16', '_mm_cmpeq_epi32', '_mm_cmpeq_epi64', '_mm_cmpeq_epi8', '_mm_cmpeq_pd', '_mm_cmpeq_ps', '_mm_cmpge_pd', '_mm_cmpge_ps', '_mm_cmpgt_epi16', '_mm_cmpgt_epi32', '_mm_cmpgt_epi8', '_mm_cmpgt_pd', '_mm_cmpgt_ps', '_mm_cmple_pd', '_mm_cmple_ps', '_mm_cmplt_pd', '_mm_cmplt_ps', '_mm_cmpneq_pd', '_mm_cmpneq_ps', '_mm_cmpord_pd', '_mm_cmpord_ps', '_mm_cvt_ss2si', '_mm_cvtepi16_epi32', '_mm_cvtepi32_epi64', '_mm_cvtepi32_pd', '_mm_cvtepi32_ps', '_mm_cvtepi8_epi16', '_mm_cvtepi8_epi32', '_mm_cvtepu16_epi32', '_mm_cvtepu32_epi64', '_mm_cvtepu8_epi16', '_mm_cvtepu8_epi32', '_mm_cvtpd_epi32', '_mm_cvtpd_ps', '_mm_cvtph_ps', '_mm_cvtps_epi32', '_mm_cvtps_pd', '_mm_cvtps_ph', '_mm_cvtsd_f64', '_mm_cvtsd_si32', '_mm_cvtsi128_si32', '_mm_cvtsi128_si64', '_mm_cvtss_f32', '_mm_cvttpd_epi32', '_mm_cvttps_epi32', '_mm_div_pd', '_mm_div_ps', '_mm_fmadd_pd', '_mm_fmadd_ps', '_mm_hadd_ps', '_mm_load_pd', '_mm_load_ps', '_mm_load_si128', '_mm_load_ss', '_mm_loadh_pi', '_mm_loadl_epi64', '_mm_loadl_pi', '_mm_loadu_pd', '_mm_loadu_ps', '_mm_loadu_si128', '_mm_madd_epi16', '_mm_max_epi16', '_mm_max_epi32', '_mm_max_epi8', '_mm_max_epu16', '_mm_max_epu32', '_mm_max_epu8', '_mm_max_pd', '_mm_max_ps', '_mm_min_epi16', '_mm_min_epi32', '_mm_min_epi8', '_mm_min_epu16', '_mm_min_epu32', '_mm_min_epu8', '_mm_min_pd', '_mm_min_ps', '_mm_movehdup_ps', '_mm_movehl_ps', '_mm_moveldup_ps', '_mm_movelh_ps', '_mm_movemask_epi8', '_mm_movemask_pd', '_mm_movemask_ps', '_mm_mul_epi32', '_mm_mul_epu32', '_mm_mul_pd', '_mm_mul_ps', '_mm_mulhi_epi16', '_mm_mulhi_epu16', '_mm_mullo_epi16', '_mm_mullo_epi32', '_mm_or_pd', '_mm_or_ps', '_mm_or_si128', '_mm_packs_epi16', '_mm_packs_epi32', '_mm_packus_epi16', '_mm_packus_epi32', '_mm_permute_ps', '_mm_popcnt_u32', '_mm_popcnt_u64', '_mm_rsqrt_ps', '_mm_sad_epu8', '_mm_set1_epi16', '_mm_set1_epi32', '_mm_set1_epi64x', '_mm_set1_epi8', '_mm_set1_pd', '_mm_set_epi32', '_mm_set_epi64x', '_mm_set_ps', '_mm_set_ps1', '_mm_set_sd', '_mm_set_ss', '_mm_setr_epi16', '_mm_setr_epi32', '_mm_setr_epi8', '_mm_setr_pd', '_mm_setr_ps', '_mm_setzero_pd', '_mm_setzero_ps', '_mm_setzero_si128', '_mm_shuffle_epi32', '_mm_shuffle_epi8', '_mm_shuffle_ps', '_mm_shufflehi_epi16', '_mm_shufflelo_epi16', '_mm_sll_epi32', '_mm_slli_epi16', '_mm_slli_epi32', '_mm_slli_epi64', '_mm_slli_si128', '_mm_sqrt_pd', '_mm_sqrt_ps', '_mm_srai_epi16', '_mm_srai_epi32', '_mm_srli_epi16', '_mm_srli_epi32', '_mm_srli_epi64', '_mm_srli_si128', '_mm_sub_epi16', '_mm_sub_epi32', '_mm_sub_epi64', '_mm_sub_epi8', '_mm_sub_pd', '_mm_sub_ps', '_mm_subs_epi16', '_mm_subs_epi8', '_mm_subs_epu16', '_mm_subs_epu8', '_mm_unpackhi_epi16', '_mm_unpackhi_epi32', '_mm_unpackhi_epi64', '_mm_unpackhi_epi8', '_mm_unpackhi_pd', '_mm_unpackhi_ps', '_mm_unpacklo_epi16', '_mm_unpacklo_epi32', '_mm_unpacklo_epi64', '_mm_unpacklo_epi8', '_mm_unpacklo_pd', '_mm_unpacklo_ps', '_mm_xor_pd', '_mm_xor_ps', '_mm_xor_si128', 'a64l', 'abs', 'acos', 'atan', 'atan2', 'atof', 'atoi', 'atol', 'calloc', 'close', 'cos', 'cvAlloc', 'dup', 'dup2', 'exp', 'fabs', 'fastMalloc', 'fchmod', 'fchown', 'fcntl', 'fileno', 'floor', 'fork', 'fputs', 'ftell', 'ftruncate', 'fwrite', 'getaddrinfo', 'getdtablesize', 'getegid', 'geteuid', 'getgid', 'getgrent', 'getgroups', 'getpagesize', 'getpgrp', 'getpid', 'getppid', 'getpwent', 'getpwnam', 'getpwuid', 'getservent', 'gettext', 'getuid', 'htonl', 'htons', 'iconv_open', 'inet_addr', 'ippicvMalloc_L', 'iswctype', 'localtime', 'log', 'log10', 'lseek', 'malloc', 'mblen', 'mbrlen', 'mbrtowc', 'mbsnrtowcs', 'mbstowcs', 'memcmp', 'memcpy', 'mmap', 'mremap', 'munmap', 'ntohl', 'ntohs', 'operator new', 'operator new[]', 'operator=', 'pow', 'printf', 'pthread_self', 'rand', 'readlink', 'realloc', 'rmdir', 'sbrk', 'setlocale', 'sigprocmask', 'sin', 'socket', 'sqrt', 'std::abs', 'std::acos', 'std::atan', 'std::atan2', 'std::basic_ostream::operator<<', 'std::floor', 'std::make_error_code', 'std::operator<<', 'std::operator|', 'strchr', 'strchrnul', 'strcmp', 'strcpy', 'strdup', 'strerror', 'strlen', 'strncasecmp', 'strncmp', 'strncpy', 'strnlen', 'strpbrk', 'strrchr', 'strsignal', 'strstr', 'strtod', 'strtoimax', 'strtol', 'strtold', 'strtoul', 'strtoull', 'strtoumax', 'strtouq', 'sysconf', 'tcgetpgrp', 'tcsetattr', 'time', 'tmpnam', 'tolower', 'toupper', 'towlower', 'towupper', 'ttyname', 'umask', 'unlink', 'vsnprintf', 'wcrtomb', 'wcscat', 'wcscpy', 'wcsdup', 'wcslen', 'wcsrtombs', 'wcswidth', 'wctob', 'wctomb', 'wctype', 'wcwidth', 'write'}
external_sources.return_values_of.functions : set[bauhaus.analysis.config.QualifiedName] =
Functions for which the return value should be considered an external value that must be checked before use. If the set is empty, all return values of external functions are checked.{'getc', 'getchar', 'getenv'}
is_acceptable_use_in_condition¶
is_acceptable_use_in_condition
If given, this predicate is used to check a condition further that involves the value received from an external source. The predicate receives the following arguments: check: The PIR node of type Conditional_Interface in whose condition the external value is used, or a Relational_Operator using it inside the operands val: The ExternalValue object representing the value received from an external source node: The PIR node representing the use of the external value use: The LIR node corresponding to the use The return value should be True iff the use of the external value inside this condition is ok (e.g. because that's a check validating the value).Type: typing.Callable[[bauhaus.ir.Node, bauhaus.rules.axivion.expressions.generic.taint_analysis.ExternalValue, bauhaus.ir.Node, bauhaus.ir.Node], bool] | None
Default:
None
is_relevant_usage¶
is_relevant_usage
If given, this predicate is used to check if a usage of tainted input is relevant for the analysis. This can be used to restrict the analysis to certain types of usages only. The predicate receives the following arguments: val: The ExternalValue object representing the value received from an external source node: The PIR node representing the use of the external value use: The LIR node corresponding to the use The return value should be True if the use of the external value inside this condition is relevant, i.e., if an error message should be issued by the rule. If the return value is False, the message is discarded.Type: typing.Callable[[bauhaus.rules.axivion.expressions.generic.taint_analysis.ExternalValue, bauhaus.ir.Node, bauhaus.ir.Node], bool] | None
Default:
None
is_sufficient_preceding_check¶
is_sufficient_preceding_check
If given, this predicate is used to check a condition further that involves the value received from an external source and which happens before the use being checked. It should also check whether the right branch was taken. The predicate receives the following arguments: check: The PIR node of type Conditional_Interface in which's condition the external value is used val: The ExternalValue object representing the value received from an external source node: The PIR node representing the use of the external value inside the condition use: The LIR node for the use being checked (after the condition) branch: The iranalysis block representing the branch taken at the condition The return value should be True iff the condition is sufficiently checking the validity of this external value.Type: typing.Callable[[bauhaus.ir.Node, bauhaus.rules.axivion.expressions.generic.taint_analysis.ExternalValue, bauhaus.ir.Node, bauhaus.ir.Node, _iranalysis.Basic_Block], bool] | None
Default:
None
maximum_reports_per_source_location¶
maximum_reports_per_source_location : int = 10
omit_implicitly_passed_this¶
omit_implicitly_passed_this : bool = True
only_report_arguments¶
only_report_arguments : bool = True
sanitizer_functions¶
sanitizer_functions
Description of sanitizing functions with the number of the sanitized argument.Type: dict[bauhaus.analysis.config.QualifiedName, ArgumentSpecifier]
Default:
{}
sanitizer_macros¶
sanitizer_macros
Description of sanitizing macros with the number of the sanitized argument.Type: dict[bauhaus.analysis.config.QualifiedName, ArgumentSpecifier]
Default:
{}
sinks¶
Description of the possible sinks for which flows of unchecked external values are reported
sinks.excluded
Functions which should be exempt from the set of functions considered as sinksType: dict[bauhaus.analysis.config.QualifiedName, ArgumentSpecifier]
Default:
{ 'free': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0}, argument_range_max=4294967295, argument_range_min=0 ) }
sinks.functions
Functions which should be in the set of functions considered as sinksType: dict[bauhaus.analysis.config.QualifiedName, ArgumentSpecifier]
Default:
{ 'CreateProcess': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0}, argument_range_max=4294967295, argument_range_min=0 ), 'CreateProcessA': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0}, argument_range_max=4294967295, argument_range_min=0 ), 'CreateProcessW': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0}, argument_range_max=4294967295, argument_range_min=0 ), '_exec': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0}, argument_range_max=4294967295, argument_range_min=0 ), '_execl': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0}, argument_range_max=4294967295, argument_range_min=0 ), '_execle': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0}, argument_range_max=4294967295, argument_range_min=0 ), '_execlp': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0}, argument_range_max=4294967295, argument_range_min=0 ), '_execv': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0}, argument_range_max=4294967295, argument_range_min=0 ), '_execvp': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0}, argument_range_max=4294967295, argument_range_min=0 ), '_execvpe': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0}, argument_range_max=4294967295, argument_range_min=0 ), '_popen': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0}, argument_range_max=4294967295, argument_range_min=0 ), '_spawnl': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={1}, argument_range_max=4294967295, argument_range_min=0 ), '_spawnlp': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={1}, argument_range_max=4294967295, argument_range_min=0 ), '_spawnv': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={1}, argument_range_max=4294967295, argument_range_min=0 ), '_spawnvp': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={1}, argument_range_max=4294967295, argument_range_min=0 ), '_wexec': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0}, argument_range_max=4294967295, argument_range_min=0 ), '_wexecl': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0}, argument_range_max=4294967295, argument_range_min=0 ), '_wexecle': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0}, argument_range_max=4294967295, argument_range_min=0 ), '_wexeclp': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0}, argument_range_max=4294967295, argument_range_min=0 ), '_wexecv': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0}, argument_range_max=4294967295, argument_range_min=0 ), '_wexecvp': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0}, argument_range_max=4294967295, argument_range_min=0 ), '_wexecvpe': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0}, argument_range_max=4294967295, argument_range_min=0 ), '_wpopen': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0}, argument_range_max=4294967295, argument_range_min=0 ), '_wspawnl': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={1}, argument_range_max=4294967295, argument_range_min=0 ), '_wspawnlp': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={1}, argument_range_max=4294967295, argument_range_min=0 ), '_wspawnv': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={1}, argument_range_max=4294967295, argument_range_min=0 ), '_wspawnvp': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={1}, argument_range_max=4294967295, argument_range_min=0 ), 'exec': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0}, argument_range_max=4294967295, argument_range_min=0 ), 'execl': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0}, argument_range_max=4294967295, argument_range_min=0 ), 'execle': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0}, argument_range_max=4294967295, argument_range_min=0 ), 'execlp': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0}, argument_range_max=4294967295, argument_range_min=0 ), 'execv': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0}, argument_range_max=4294967295, argument_range_min=0 ), 'execvp': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0}, argument_range_max=4294967295, argument_range_min=0 ), 'execvpe': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0}, argument_range_max=4294967295, argument_range_min=0 ), 'popen': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0}, argument_range_max=4294967295, argument_range_min=0 ), 'system': bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier( argument_numbers_set={0}, argument_range_max=4294967295, argument_range_min=0 ) }
Option Types¶
These types are used by options listed above:
ArgumentSpecifier¶
Specification of which argument positions to consider: An argument at position x is included if ALL of the following conditions are met: * x is within the specified range: argument_range_min ≤ x ≤ argument_range_max * Either no specific arguments are listed (argument_numbers_set is empty), OR x is explicitly listed in argument_numbers_set Examples: * To target the first 5 variadic arguments of sscanf (positions 2-6): set argument_range_min = 2, argument_range_max = 6, leave argument_numbers_set empty * To target only the format string of sscanf (position 1): set argument_numbers_set = {1} and keep default values for argument_range_min and argument_range_maxargument_numbers_set : set[int] = set()
argument_range_max : int = 4294967295
argument_range_min : int = 0