CVE-2023-49797 Information

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.

CVSS Vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Reference

https://github.com/pyinstaller/pyinstaller/security/advisories/GHSA-9w2p-rh8c-v9g5 https://github.com/pyinstaller/pyinstaller/pull/7827 https://github.com/python/cpython/blob/0fb18b02c8ad56299d6a2910be0bab8ad601ef24/Lib/shutil.py#L623

Attack Complexity

LOW

Privileges Required

LOW

User Interaction Required

LOW

Scope

NONE

Confidentiality Impact

UNCHANGED

Integrity Impact

HIGH

Availability Impact

HIGH

Base Score

HIGH

Base Severity

7.8