What’s Vulnerable › Vulnerabilities
CVE-2023-49797: Local Privilege Escalation in pyinstaller on Windows
- Severity: high (CVSS 7.8 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.3% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2023-12-09 · updated 2026-06-17
- Weakness: CWE-379
Description
PyInstaller bundles a Python application and all its dependencies into a single package. 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: 1. The user runs an application containing either `matplotlib` or `win32com`. 2. The application is ran as administrator (or at least a user with higher privileges than the attacker). 3. 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: A. 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 B: The application was built with Python 3.7.x or earlier which has no protection against Directory Junctions links. The vulnerability has been addressed in PR #7827 which corresponds to `pyinstaller >= 5.13.1`. Users are advised to upgrade. There are no known workarounds for this vulnerability.
Affected products
- pyinstaller: before 5.13.1 — fixed in 5.13.1
How to fix
Upgrade to a fixed version: pyinstaller 5.13.1. Check the vendor advisory for mitigations.
References
- https://github.com/pyinstaller/pyinstaller/pull/7827
- https://github.com/pyinstaller/pyinstaller/security/advisories/GHSA-9w2p-rh8c-v9g5
- https://github.com/python/cpython/blob/0fb18b02c8ad56299d6a2910be0bab8ad601ef24/Lib/shutil.py#L623
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/2K2XIQLEMZIKUQUOWNDYWTEWYQTKMAN7/
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/ISRWT34FAF23PUOLVZ7RVWBZMWPDR5U7/
- https://github.com/pyinstaller/pyinstaller/pull/7827
- https://github.com/pyinstaller/pyinstaller/security/advisories/GHSA-9w2p-rh8c-v9g5
- https://github.com/python/cpython/blob/0fb18b02c8ad56299d6a2910be0bab8ad601ef24/Lib/shutil.py#L623
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/2K2XIQLEMZIKUQUOWNDYWTEWYQTKMAN7/
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/ISRWT34FAF23PUOLVZ7RVWBZMWPDR5U7/
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