CVE-2023-49797

Local Privilege Escalation in Windows

Workarounds

Is there a way for users to fix or remediate the vulnerability without upgrading?

No workaround, although the attack complexity becomes much higher if the application is built with Python >= 3.8.0.

A PyInstaller built application, elevated as a privileged process, may be tricked by an unprivileged attacker into deleting files the unprivileged user does not otherwise have access to.

A user is affected if all the following are satisfied:

• The user runs an application containing either matplotlib or win32com.
• The application is ran as administrator (or at least a user with higher privileges than the attacker).
• The user's temporary directory is not locked to that specific user (most likely due to TMP/TEMP environment variables pointing to an unprotected, arbitrary, non default location).
• Either:
  • The attacker is able to very carefully time the replacement of a temporary file with a symlink. This switch must occur exactly between shutil.rmtree()'s builtin symlink check and the deletion itself
  • The application was built with Python 3.7.x or earlier which has no protection against Directory Junctions links

A file, directory, or other resource is assigned permissions that allow broader access than intended. Typical impact: unauthorized read, modification, or execution of the resource.

CVE-2023-49797 has a CVSS score of 8.8 (High). The vector is requires local access, low privileges required, and no user interaction. 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 (5.13.1); upgrading removes the vulnerable code path.

Kodem intelligence

Already deployed Kodem?

The vulnerability has been addressed in https://github.com/pyinstaller/pyinstaller/pull/7827 which corresponds to pyinstaller >= 5.13.1

1. What is CVE-2023-49797? CVE-2023-49797 is a high-severity incorrect permission assignment for critical resource vulnerability in pyinstaller (pip), affecting versions < 5.13.1. It is fixed in 5.13.1. A file, directory, or other resource is assigned permissions that allow broader access than intended.
2. How severe is CVE-2023-49797? CVE-2023-49797 has a CVSS score of 8.8 (High). 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 pyinstaller are affected by CVE-2023-49797? pyinstaller (pip) versions < 5.13.1 is affected.
4. Is there a fix for CVE-2023-49797? Yes. CVE-2023-49797 is fixed in 5.13.1. Upgrade to this version or later.
5. Is CVE-2023-49797 exploitable, and should I be worried? Whether CVE-2023-49797 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-2023-49797 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-2023-49797? Upgrade pyinstaller to 5.13.1 or later.

Other vulnerabilities in pyinstaller