CVE-2019-12761: Pyxdg Code Injection Vulnerability

HIGH
Advisory Identifier: GHSA-r6v3-hpxj-r8rv
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CVSS 7.5
CWE-94
Published
Advisory Summary

CVE-2019-12761 is a HIGH (CVSS 7.5) code injection vulnerability (CWE-94: Improper Control of Generation of Code ('Code Injection')) affecting Pyxdg libraries in the PyPI ecosystem. The issue involves code injection in pyxdg. Remediation is available by upgrading affected packages to version 0.26.

CVE-2019-12761 at a Glance

CVE Identifier CVE-2019-12761
GHSA Identifier GHSA-r6v3-hpxj-r8rv
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-94: Improper Control of Generation of Code ('Code Injection')
Affected Product Pyxdg
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 7.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H).

Attack Vector Network (AV:N)
Attack Complexity High (AC:H)
Privileges Required None (PR:N)
User Interaction Required (UI:R)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2019-12761

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

pyxdg fixed: 0.26 
pip install pyxdg>=0.26
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 pyxdg

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2019-12761, inspect your installed packages using pip:

pip show pyxdg

Analyze the terminal output to locate any version of Pyxdg in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.26), your application is affected.

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

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-94: Improper Control of Generation of Code ('Code Injection'), where the product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment. In Pyxdg, 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

A code injection issue was discovered in PyXDG before 0.26 via crafted Python code in a Category element of a Menu XML document in a .menu file. XDG_CONFIG_DIRS must be set up to trigger xdg.Menu.parse parsing within the directory containing this file. This is due to a lack of sanitization in xdg/Menu.py before an eval call.

CVE-2019-12761 Affected Pyxdg Versions

1 component(s)
Fixed Versions:
0.26
Product / Package Ecosystem Affected Versions Fixed Version
pyxdg
pypi/pyxdg
PyPI
< 0.26
0.26

References

NVD — CVE-2019-12761 NVD
https://nvd.nist.gov/vuln/detail/CVE-2019-12761
Pyxdg Source Repository REPOSITORY
https://gist.github.com/dhondta/b45cd41f4186110a354dc7272916feba
Pyxdg Source Repository REPOSITORY
https://github.com/pypa/advisory-database/tree/main/vulns/pyxdg/PYSEC-2019-199.yaml
Pyxdg Source Repository REPOSITORY
https://github.com/takluyver/pyxdg
lists.debian.org/debian-lts-announce... WEB
https://lists.debian.org/debian-lts-announce/2019/06/msg00006.html
lists.debian.org/debian-lts-announce... WEB
https://lists.debian.org/debian-lts-announce/2021/08/msg00003.html
snyk.io/vuln/snyk-python-py... WEB
https://snyk.io/vuln/SNYK-PYTHON-PYXDG-174562

Frequently Asked Questions

What is CVE-2019-12761?
CVE-2019-12761 is a security vulnerability in Pyxdg involving Code Injection in PyXDG under CWE-94: Improper Control of Generation of Code ('Code Injection').
Which Pyxdg versions are affected?
Affected versions include releases prior to 0.26 across affected packages: pyxdg.
What version fixes CVE-2019-12761?
Upgrading to 0.26 (or the latest patched release for your respective branch) resolves the vulnerability.
Is pyxdg affected?
Yes, pyxdg is affected in releases prior to 0.26. Upgrade your dependency to 0.26 or later.
What is the CVSS score of CVE-2019-12761?
CVE-2019-12761 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2019-12761?
CVE-2019-12761 is classified under CWE-94: Improper Control of Generation of Code ('Code Injection') (The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.).
How can I check PyPI dependencies for CVE-2019-12761?
Run the dependency tree command: 'pip show pyxdg'. 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
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-r6v3-hpxj-r8rv",
  "modified" : "2024-10-15T16:41:13Z",
  "published" : "2019-06-07T20:56:27Z",
  "aliases" : [ "CVE-2019-12761" ],
  "summary" : "Code Injection in PyXDG",
  "details" : "A code injection issue was discovered in PyXDG before 0.26 via crafted Python code in a Category element of a Menu XML document in a .menu file. XDG_CONFIG_DIRS must be set up to trigger xdg.Menu.parse parsing within the directory containing this file. This is due to a lack of sanitization in xdg/Menu.py before an eval call.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "pyxdg"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.26"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2019-12761"
  }, {
    "type" : "WEB",
    "url" : "https://gist.github.com/dhondta/b45cd41f4186110a354dc7272916feba"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/pypa/advisory-database/tree/main/vulns/pyxdg/PYSEC-2019-199.yaml"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/takluyver/pyxdg"
  }, {
    "type" : "WEB",
    "url" : "https://lists.debian.org/debian-lts-announce/2019/06/msg00006.html"
  }, {
    "type" : "WEB",
    "url" : "https://lists.debian.org/debian-lts-announce/2021/08/msg00003.html"
  }, {
    "type" : "WEB",
    "url" : "https://snyk.io/vuln/SNYK-PYTHON-PYXDG-174562"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-94" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2019-06-07T10:24:55Z",
    "nvd_published_at" : "2019-06-06T19:29:00Z"
  }
}