CVE-2022-23530

Unsafe extracting using shutil.unpack_archive() from a remotely retrieved tarball may lead to writing the extracted file to an unintended destination.

Details

Extracting files using shutil.unpack_archive() from a potentially malicious tarball without validating that the destination file path is within the intended destination directory can cause files outside the destination directory to be overwritten.

The vulnerable code snippet is between L153..158.

response = requests.get(url, stream=True)

with open(zippath, "wb") as f:
      f.write(response.raw.read())

shutil.unpack_archive(zippath, unzippedpath)

It seems that a remotely retrieved tarball which could be with the extension .tar.gz happens to be unpacked using shutil.unpack_archive() with no destination verification/limitation of the extracted files.

PoC

The PoC provided showcases the risk of extracting the non-harmless text file sim4n6.txt to a parent location rather than the current folder.

> tar --list -f archive.tar
tar: Removing leading `../../../' from member names
../../../sim4n6.txt

> python3 
Python 3.10.6 (main, Nov  2 2022, 18:53:38) [GCC 11.3.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import shutil
>>> shutil.unpack_archive("archive.tar")
>>> exit()

> file ../../../sim4n6.txt
../../../sim4n6.txt: ASCII text

A Potential Attack Scenario

• An attacker may craft a malicious tarball with a filename path, such as ../../../../../../../../etc/passwd, and then serve the archive remotely, thus, providing a possibility to overwrite the system files.

Mitigation

Potential mitigation could be to:

• Use a safer module, like zipfile.
• Validate the location of the extracted files and discard those with malicious paths such as a relative path .. or absolute ones.

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.

CVE-2022-23530 has a CVSS score of 5.8 (Low). The vector is network-reachable, no privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (0.1.8); upgrading removes the vulnerable code path.

Kodem intelligence

1. What is CVE-2022-23530? CVE-2022-23530 is a low-severity path traversal vulnerability in guarddog (pip), affecting versions <= 0.1.7. It is fixed in 0.1.8. Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files.
2. How severe is CVE-2022-23530? CVE-2022-23530 has a CVSS score of 5.8 (Low). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of guarddog are affected by CVE-2022-23530? guarddog (pip) versions <= 0.1.7 is affected.
4. Is there a fix for CVE-2022-23530? Yes. CVE-2022-23530 is fixed in 0.1.8. Upgrade to this version or later.
5. Is CVE-2022-23530 exploitable, and should I be worried? Whether CVE-2022-23530 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
6. What actually determines whether CVE-2022-23530 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.
7. How do I fix CVE-2022-23530? Upgrade guarddog to 0.1.8 or later.