Summary
setuptools has a path traversal vulnerability in PackageIndex.download that leads to Arbitrary File Write
A path traversal vulnerability in PackageIndex was fixed in setuptools version 78.1.1
Details
def _download_url(self, url, tmpdir):
# Determine download filename
#
name, _fragment = egg_info_for_url(url)
if name:
while '..' in name:
name = name.replace('..', '.').replace('\\', '_')
else:
name = "__downloaded__" # default if URL has no path contents
if name.endswith('.[egg.zip](http://egg.zip/)'):
name = name[:-4] # strip the extra .zip before download
--> filename = os.path.join(tmpdir, name)
os.path.join() discards the first argument tmpdir if the second begins with a slash or drive letter.name is derived from a URL without sufficient sanitization. While there is some attempt to sanitize by replacing instances of '..' with '.', it is insufficient.
Risk Assessment
As easy_install and package_index are deprecated, the exploitation surface is reduced.
However, it seems this could be exploited in a similar fashion like https://github.com/advisories/GHSA-r9hx-vwmv-q579, and as described by POC 4 in https://github.com/advisories/GHSA-cx63-2mw6-8hw5 report: via malicious URLs present on the pages of a package index.
References
https://huntr.com/bounties/d6362117-ad57-4e83-951f-b8141c6e7ca5
https://github.com/pypa/setuptools/issues/4946
Impact
An attacker would be allowed to write files to arbitrary locations on the filesystem with the permissions of the process running the Python code, which could escalate to RCE depending on the context.
Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files. Typical impact: unauthorized file read or write outside the intended directory.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Frequently Asked Questions
- What is CVE-2025-47273? CVE-2025-47273 is a high-severity path traversal vulnerability in setuptools (pip), affecting versions < 78.1.1. It is fixed in 78.1.1. Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files.
- Which versions of setuptools are affected by CVE-2025-47273? setuptools (pip) versions < 78.1.1 is affected.
- Is there a fix for CVE-2025-47273? Yes. CVE-2025-47273 is fixed in 78.1.1. Upgrade to this version or later.
- Is CVE-2025-47273 exploitable, and should I be worried? Whether CVE-2025-47273 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2025-47273 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2025-47273? Upgrade
setuptoolsto 78.1.1 or later.