Vulnerability in Pyinstaller
CVE-2023-49797
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.003 (23.0th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 23rd percentile — 23.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000
Affected products
- Pyinstaller — versions < 5.13.1
Weakness classification (CWE)
Public proof-of-concept exploits
References
- github.com/pyinstaller/pyinstaller/security/advisories/GHSA-9w2p-rh8c-v9g5 (Vendor Advisory)
- github.com/pyinstaller/pyinstaller/pull/7827 (Patch, Issue Tracking)
- github.com/python/cpython/blob/0fb18b02c8ad56299d6a2910be0bab8ad601ef24/Lib/shu… (Product)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/…
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/…
Frequently asked questions
- What is CVE-2023-49797?
- CVE-2023-49797 is a high-severity vulnerability in Pyinstaller, classified under Creation of Temporary File in Directory with Insecure Permissions. CVSS score: 8.8/10. Published 2023-12-09.
- How severe is CVE-2023-49797?
- High severity. CVSS v3 base score is 8.8 out of 10.
- Is CVE-2023-49797 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.