CyberSecBulletin
CVE-2024-9287NVD status: Modified

CPython: Improper Neutralization of Special Elements used in a Command

Published Updated By the CyberSecBulletin desk

CVE-2024-9287 is a high-severity improper neutralization of special elements used in a command vulnerability in CPython from Python Software Foundation, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists versions 3.9.21, 3.10.16, 3.11.11 as the first without the flaw, so updating CPython to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.65% chance of exploitation within 30 days, higher than 52% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update CPython to 3.9.21 or 3.10.16 or 3.11.11 or 3.12.8, whichever matches your release line, or a later version.
  2. Update Python to 3.9.21 or 3.10.16 or 3.11.11 or 3.12.8, whichever matches your release line, or a later version.
  3. Read the advisory on mail.python.org for workarounds and exact fixed builds.

Affected products and versions

VendorProductAffected versionsFixed in
Python Software FoundationCPythonbefore 3.9.21; 3.10.0 up to, but not including, 3.10.16; 3.11.0 up to, but not including, 3.11.11; 3.12.0 up to, but not including, 3.12.8; 3.13.0 up to, but not including, 3.13.1; 3.14.0a1 up to, but not including, 3.14.0a23.9.21, 3.10.16, 3.11.11, 3.12.8, 3.13.1, 3.14.0a2
PythonPythonbefore 3.9.21; 3.10.0 up to, but not including, 3.10.16; 3.11.0 up to, but not including, 3.11.11; 3.12.0 up to, but not including, 3.12.8; 3.13.0 up to, but not including, 3.13.1; 3.14.03.9.21, 3.10.16, 3.11.11, 3.12.8, 3.13.1

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 4.05.3MediumCNA (python.org)
CVSS 3.17.8HighNVD

Official description

A vulnerability has been found in the CPython `venv` module and CLI where path names provided when creating a virtual environment were not quoted properly, allowing the creator to inject commands into virtual environment "activation" scripts (ie "source venv/bin/activate"). This means that attacker-controlled virtual environments are able to run commands when the virtual environment is activated. Virtual environments which are not created by an attacker or which aren't activated before being used (ie "./venv/bin/python") are not affected.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Improper Neutralization of Special Elements used in a Command

The product constructs all or part of a command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended command when it is sent to a downstream component.

How developers prevent this class of flaw

  • If at all possible, use library calls rather than external processes to recreate the desired functionality.
  • If possible, ensure that all external commands called from the program are statically created.
  • Run time: Run time policy enforcement may be used in an allowlist fashion to prevent use of any non-sanctioned commands.

More Improper Neutralization of Special Elements used in a Command vulnerabilities (CWE-77)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in CPython

All CPython vulnerabilities

Recent Improper Neutralization of Special Elements used in a Command vulnerabilities

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