CWE-36¶

Absolute Path Traversal. [Improper-Control-Of-A-Resource-Through-Its-Lifetime]

Required inputs: IR, StaticSemanticAnalysis

The product uses external input to construct a pathname that should be within a restricted directory, but it does not properly neutralize absolute path sequences such as "/abs/path" that can resolve to a location that is outside of that directory. This allows attackers to traverse the file system to access files or directories that are outside of the restricted directory.

Demonstrative Examples

Example 1

In the example below, the path to a dictionary file is read from a system property and used to initialize a File object.

Example Language:Java (Unsupported language for documentation only)
    String filename = System.getProperty("com.domain.application.dictionaryFile");
    File dictionaryFile = new File(filename);

However, the path is not validated or modified to prevent it from containing relative or absolute path sequences before creating the File object. This allows anyone who can control the system property to determine what file is used. Ideally, the path should be resolved relative to some kind of application or user home directory.

Example 2

This script intends to read a user-supplied file from the current directory. The user inputs the relative path to the file and the script uses Python's os.path.join() function to combine the path to the current working directory with the provided path to the specified file. This results in an absolute path to the desired file. If the file does not exist when the script attempts to read it, an error is printed to the user.

Example Language:Python (Unsupported language for documentation only)
    import os
    import sys
    def main():

        filename = sys.argv[1]
        path = os.path.join(os.getcwd(), filename)
        try:

            with open(path, 'r') as f:

                file_data = f.read()
        except FileNotFoundError as e:

            print("Error - file not found")
    main()

However, if the user supplies an absolute path, the os.path.join() function will discard the path to the current working directory and use only the absolute path provided. For example, if the current working directory is /home/user/documents, but the user inputs /etc/passwd, os.path.join() will use only /etc/passwd, as it is considered an absolute path. In the above scenario, this would cause the script to access and read the /etc/passwd file.

Example Language:Python (Unsupported language for documentation only)
    import os
    import sys
    def main():

        filename = sys.argv[1]
        path = os.path.normpath(f"{os.getcwd()}{os.sep}{filename}")
        if path.startswith("/home/cwe/documents/"):

            try:

                with open(path, 'r') as f:

                    file_data = f.read()
            except FileNotFoundError as e:

                print("Error - file not found")
    main()

The constructed path string uses os.sep to add the appropriate separation character for the given operating system (e.g. '\' or '/') and the call to os.path.normpath() removes any additional slashes that may have been entered - this may occur particularly when using a Windows path. The path is checked against an expected directory (/home/cwe/documents); otherwise, an attacker could provide relative path sequences like ".." to cause normpath() to generate paths that are outside the intended directory (CWE-23). By putting the pieces of the path string together in this fashion, the script avoids a call to os.path.join() and any potential issues that might arise if an absolute path is entered. With this version of the script, if the current working directory is /home/cwe/documents, and the user inputs /etc/passwd, the resulting path will be /home/cwe/documents/etc/passwd. The user is therefore contained within the current working directory as intended.

Possible Messages

Key	Text	Severity	Disabled
unchecked_external_value	Path to executable received from external sources shall be checked.	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

If true, consider all external functions as possible sinks, for which consuming unchecked inputs of interest shall be reported. To exclude particular external functions, please use the sinks option.

all_external_functions_as_sources¶

all_external_functions_as_sources : bool = True

If true, consider all external functions as possible origin of values whose unchecked consumption by sinks shall be reported. To exclude particular external functions, please use the external_sources option.

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 number x is considered iff (x >= argument_range_min and x <= argument_range_max and argument_numbers_set.empty()) or x in argument_numbers_set. If the table is empty, all non-const pointer parameters of external functions are checked.

external_sources.arguments_of.excluded

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
   )
}

Functions which should be exempt from the set of functions for which the arguments should be checked before using them.

external_sources.arguments_of.functions

Type: 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
   )
}

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 the arguments_of.excluded option.

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] = set()
Functions which should be exempt from the set of functions for which the parameters should be checked before using them.

external_sources.parameters_of.functions : set[bauhaus.analysis.config.QualifiedName] = set()
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.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

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'}

Functions which should be exempt from the set of functions for which the return value should be treated as an external value.

external_sources.return_values_of.functions : set[bauhaus.analysis.config.QualifiedName] = {'getc', 'getchar', 'getenv'}
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.

is_acceptable_use_in_condition¶

is_acceptable_use_in_condition

Type: typing.Callable[[bauhaus.ir.Node, bauhaus.rules.axivion.expressions.generic.taint_analysis.ExternalValue, bauhaus.ir.Node, bauhaus.ir.Node], bool] | None

Default: None

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).

is_relevant_usage¶

is_relevant_usage

Type: typing.Callable[[bauhaus.rules.axivion.expressions.generic.taint_analysis.ExternalValue, bauhaus.ir.Node, bauhaus.ir.Node], bool] | None

Default: None

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.

is_sufficient_preceding_check¶

is_sufficient_preceding_check

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

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.

maximum_reports_per_source_location¶

maximum_reports_per_source_location : int = 10

Maximum number of reported sinks per source location. For no limitation of reported sinks per source, set to 0. Caution: no limitation here may lead to a substantial amount of reported issues.

omit_implicitly_passed_this¶

omit_implicitly_passed_this : bool = True

If true, do not report implicitly passed this arguments.

only_report_arguments¶

only_report_arguments : bool = True

If true, only report arguments to sink functions. Otherwise, report all usages of tainted values.

sanitizer_functions¶

sanitizer_functions

Type: dict[bauhaus.analysis.config.QualifiedName, ArgumentSpecifier]

Default: {}

Description of sanitizing functions with the number of the sanitized argument.

sanitizer_macros¶

sanitizer_macros

Type: dict[bauhaus.analysis.config.QualifiedName, ArgumentSpecifier]

Default: {}

Description of sanitizing macros with the number of the sanitized argument.

sinks¶

Description of the possible sinks for which flows of unchecked external values are reported

sinks.excluded
Type: 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
   )
}
Functions which should be exempt from the set of functions considered as sinks

sinks.functions

Type: dict[bauhaus.analysis.config.QualifiedName, ArgumentSpecifier]

Default:

{
   'CreateFile':    bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier(
      argument_numbers_set={0},
      argument_range_max=4294967295,
      argument_range_min=0
   ),
   'CreateFileA':    bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier(
      argument_numbers_set={0},
      argument_range_max=4294967295,
      argument_range_min=0
   ),
   'CreateFileW':    bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier(
      argument_numbers_set={0},
      argument_range_max=4294967295,
      argument_range_min=0
   ),
   'OpenFile':    bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier(
      argument_numbers_set={0},
      argument_range_max=4294967295,
      argument_range_min=0
   ),
   'OpenFileA':    bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier(
      argument_numbers_set={0},
      argument_range_max=4294967295,
      argument_range_min=0
   ),
   'OpenFileW':    bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier(
      argument_numbers_set={0},
      argument_range_max=4294967295,
      argument_range_min=0
   ),
   '_open':    bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier(
      argument_numbers_set={0},
      argument_range_max=4294967295,
      argument_range_min=0
   ),
   'fopen':    bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier(
      argument_numbers_set={0},
      argument_range_max=4294967295,
      argument_range_min=0
   ),
   'freopen':    bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier(
      argument_numbers_set={0},
      argument_range_max=4294967295,
      argument_range_min=0
   ),
   'open':    bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier(
      argument_numbers_set={0},
      argument_range_max=4294967295,
      argument_range_min=0
   ),
   'std::basic_ifstream::basic_ifstream':    bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier(
      argument_numbers_set={1},
      argument_range_max=4294967295,
      argument_range_min=0
   ),
   'std::basic_ifstream::open':    bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier(
      argument_numbers_set={1},
      argument_range_max=4294967295,
      argument_range_min=0
   ),
   'std::basic_ofstream::basic_ofstream':    bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier(
      argument_numbers_set={1},
      argument_range_max=4294967295,
      argument_range_min=0
   ),
   'std::basic_ofstream::open':    bauhaus.rules.axivion.expressions.generic.taint_analysis.ArgumentSpecifier(
      argument_numbers_set={1},
      argument_range_max=4294967295,
      argument_range_min=0
   )
}

Functions which should be in the set of functions considered as sinks

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_max

argument_numbers_set : set[int] = set()

Explicit set of argument numbers to be considered. If empty, all numbers of the interval defined by [argument_range_min; argument_range_max] are considered.

argument_range_max : int = 4294967295

Maximum of the interval of numbers to be considered.

argument_range_min : int = 0

Minimum of the interval of numbers to be considered.

Axivion Suite 7.12.0

Navigation

CWE-36¶

Demonstrative Examples

Example 1

Example 2

Options¶

all_external_functions_as_sinks¶

all_external_functions_as_sources¶

external_sources¶

is_acceptable_use_in_condition¶

is_relevant_usage¶

is_sufficient_preceding_check¶

maximum_reports_per_source_location¶

omit_implicitly_passed_this¶

only_report_arguments¶

sanitizer_functions¶

sanitizer_macros¶

sinks¶

Option Types¶

ArgumentSpecifier¶