CVE Vulnerabilities

CVE-2023-49797

Incorrect Permission Assignment for Critical Resource

Published: Dec 09, 2023 | Modified: Dec 19, 2023
CVSS 3.x
7.8
HIGH
Source:
NVD
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CVSS 2.x
RedHat/V2
RedHat/V3
Ubuntu

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 users 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.

Weakness

The product specifies permissions for a security-critical resource in a way that allows that resource to be read or modified by unintended actors.

Affected Software

Name Vendor Start Version End Version
Pyinstaller Pyinstaller * 5.13.1 (excluding)

Potential Mitigations

  • Run the code in a “jail” or similar sandbox environment that enforces strict boundaries between the process and the operating system. This may effectively restrict which files can be accessed in a particular directory or which commands can be executed by the software.
  • OS-level examples include the Unix chroot jail, AppArmor, and SELinux. In general, managed code may provide some protection. For example, java.io.FilePermission in the Java SecurityManager allows the software to specify restrictions on file operations.
  • This may not be a feasible solution, and it only limits the impact to the operating system; the rest of the application may still be subject to compromise.
  • Be careful to avoid CWE-243 and other weaknesses related to jails.

References