Описание
Local Privilege Escalation in Windows
Impact
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
matplotliborwin32com. - 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/TEMPenvironment 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
- The attacker is able to very carefully time the replacement of a temporary file with a symlink. This switch must occur exactly between
Patches
The vulnerability has been addressed in https://github.com/pyinstaller/pyinstaller/pull/7827 which corresponds to pyinstaller >= 5.13.1
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.
Ссылки
- https://github.com/pyinstaller/pyinstaller/security/advisories/GHSA-9w2p-rh8c-v9g5
- https://nvd.nist.gov/vuln/detail/CVE-2023-49797
- https://github.com/pyinstaller/pyinstaller/pull/7827
- https://github.com/pypa/advisory-database/tree/main/vulns/pyinstaller/PYSEC-2023-292.yaml
- 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
Пакеты
pyinstaller
< 5.13.1
5.13.1
Связанные уязвимости
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