CVE-2023-49797: Pyinstaller Local Privilege Escalation Vulnerability

HIGH
Advisory Identifier: GHSA-9w2p-rh8c-v9g5
CVSS 8.8
CWE-379 CWE-732
Published
Advisory Summary

CVE-2023-49797 is a HIGH (CVSS 8.8) local privilege escalation vulnerability (CWE-379: Creation of Temporary File in Directory with Insecure Permissions) affecting Pyinstaller libraries in the PyPI ecosystem. The issue involves local privilege escalation in windows. Remediation is available by upgrading affected packages to version 5.13.1.

CVE-2023-49797 at a Glance

CVE Identifier CVE-2023-49797
GHSA Identifier GHSA-9w2p-rh8c-v9g5
Severity HIGH
CVSS v3.1 Base Score 8.8
CWE Classification CWE-379: Creation of Temporary File in Directory with Insecure Permissions
Affected Product Pyinstaller
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 8.8

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H).

Attack Vector Local (AV:L)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
User Interaction None (UI:N)
Scope Changed (S:C)
Confidentiality High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2023-49797

To remediate this vulnerability, upgrade all affected Pyinstaller dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

pyinstaller fixed: 5.13.1
pip install pyinstaller>=5.13.1
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release:

pip show pyinstaller

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2023-49797, inspect your installed packages using pip:

pip show pyinstaller

Analyze the terminal output to locate any version of Pyinstaller in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 5.13.1), your application is affected.

Note: The pip show pyinstaller command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-379: Creation of Temporary File in Directory with Insecure Permissions, where the product creates a temporary file in a directory whose permissions allow unintended actors to determine the file's existence or otherwise access that file. In Pyinstaller, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### 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 `matplotlib` or `win32com`. * 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`/`TEMP` environment 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](https://github.com/python/cpython/blob/0fb18b02c8ad56299d6a2910be0bab8ad601ef24/Lib/shutil.py#L623) and the deletion itself - The application was built with Python 3.7.x or earlier which has no protection against Directory Junctions links ### 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.

CVE-2023-49797 Affected Pyinstaller Versions

1 component(s)
Fixed Versions:
5.13.1
Product / Package Ecosystem Affected Versions Fixed Version
pyinstaller
PyPI
< 5.13.1
5.13.1

References

Frequently Asked Questions

What is CVE-2023-49797?
CVE-2023-49797 is a security vulnerability in Pyinstaller involving Local Privilege Escalation in Windows under CWE-379: Creation of Temporary File in Directory with Insecure Permissions.
Which Pyinstaller versions are affected?
Affected versions include releases prior to 5.13.1 across affected packages: pyinstaller.
What version fixes CVE-2023-49797?
Upgrading to 5.13.1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is pyinstaller affected?
Yes, pyinstaller is affected in releases prior to 5.13.1. Upgrade your dependency to 5.13.1 or later.
What is the CVSS score of CVE-2023-49797?
CVE-2023-49797 has a CVSS v3.1 base score of 8.8 (HIGH) with vector string CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H.
What CWE is associated with CVE-2023-49797?
CVE-2023-49797 is classified under CWE-379: Creation of Temporary File in Directory with Insecure Permissions (The product creates a temporary file in a directory whose permissions allow unintended actors to determine the file's existence or otherwise access that file.).
How can I check PyPI dependencies for CVE-2023-49797?
Run the dependency tree command: 'pip show pyinstaller'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-9w2p-rh8c-v9g5",
  "modified" : "2024-11-22T20:21:21Z",
  "published" : "2023-12-09T00:39:46Z",
  "aliases" : [ "CVE-2023-49797" ],
  "summary" : "Local Privilege Escalation in Windows",
  "details" : "### Impact\n\nA 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.\n\nA user is affected if **all** the following are satisfied:\n\n* The user runs an application containing either `matplotlib` or `win32com`.\n* The application is ran as administrator (or at least a user with higher privileges than the attacker).\n* 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).\n* Either:\n  - 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](https://github.com/python/cpython/blob/0fb18b02c8ad56299d6a2910be0bab8ad601ef24/Lib/shutil.py#L623) and the deletion itself\n  - The application was built with Python 3.7.x or earlier which has no protection against Directory Junctions links\n\n### Patches\n\nThe vulnerability has been addressed in https://github.com/pyinstaller/pyinstaller/pull/7827 which corresponds to `pyinstaller >= 5.13.1`\n\n### Workarounds\n_Is there a way for users to fix or remediate the vulnerability without upgrading?_\n\nNo workaround, although the attack complexity becomes much higher if the application is built with Python >= 3.8.0.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "pyinstaller"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "5.13.1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/pyinstaller/pyinstaller/security/advisories/GHSA-9w2p-rh8c-v9g5"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2023-49797"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/pyinstaller/pyinstaller/pull/7827"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/pyinstaller/pyinstaller"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/pypa/advisory-database/tree/main/vulns/pyinstaller/PYSEC-2023-292.yaml"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/python/cpython/blob/0fb18b02c8ad56299d6a2910be0bab8ad601ef24/Lib/shutil.py#L623"
  }, {
    "type" : "WEB",
    "url" : "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/2K2XIQLEMZIKUQUOWNDYWTEWYQTKMAN7"
  }, {
    "type" : "WEB",
    "url" : "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/ISRWT34FAF23PUOLVZ7RVWBZMWPDR5U7"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-379", "CWE-732" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2023-12-09T00:39:46Z",
    "nvd_published_at" : "2023-12-09T01:15:07Z"
  }
}