300
301
302def rstfile_to_description(path, filename, fix_urls):
303 html = subprocess.check_output(304 ['pandoc', path, '--no-highlight', '-f', 'rst', '-t', 'html5'])305 footer = """<h2>References</h2>
306<p><a href="%s%s.html" target="_blank">clang.llvm.org</a></p>""" % (CLANG_TIDY_DOC_URL_BASE, filename)
307 if fix_urls:Python possesses many mechanisms to invoke an external executable. If the desired executable path is not fully qualified relative to the filesystem root then this may present a potential security risk.
In POSIX environments, the PATH environment variable is used to specify a set of standard locations that will be searched for the first matching named executable. While convenient, this behavior may allow a malicious actor to exert control over a system. If they are able to adjust the contents of the PATH variable, or manipulate the file system, then a bogus executable may be discovered in place of the desired one. This executable will be invoked with the user privileges of the Python process that spawned it, potentially a highly privileged user.
This test will scan the parameters of all configured Python methods, looking for paths that do not start at the filesystem root, that is, do not have a leading ‘/’ character.
Bad practice
import subprocess
subprocess.run(['calculator', '-u', 'critical', msg], check=True) # Sensitive, Path not qualified from root
Recommended
import subprocess
subprocess.run(['/usr/bin/calculator', '-u', 'critical', msg], check=True) # Path qualified from root
References:
- Bandit B607
- OWASP Top 10 2021 Category A03 - Injection