CyberSecBulletin
CVE-2022-41953NVD status: Modified

git: Untrusted Search Path

Published Updated By the CyberSecBulletin desk

CVE-2022-41953 is a high-severity untrusted search path vulnerability in git from Git-for-windows, 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 unauthenticated attacker, but only if a user takes part, for example by opening a link or file. Affected git versions: < 2.39.1. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 8.04% chance of exploitation within 30 days, which is in the top 5.13% of all scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of git you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on github.com for workarounds and exact fixed builds.
  3. Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.

Affected products and versions

VendorProductAffected versionsFixed in
Git-for-windowsgit< 2.39.1Not stated

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
NoneNo account or login is needed.
User interaction
RequiredA user must take an action such as opening a file or link.
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:N/UI:R/S:U/C:H/I:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.18.6HighCNA (github.com)
CVSS 3.17.8HighNVD

Official description

Git GUI is a convenient graphical tool that comes with Git for Windows. Its target audience is users who are uncomfortable with using Git on the command-line. Git GUI has a function to clone repositories. Immediately after the local clone is available, Git GUI will automatically post-process it, among other things running a spell checker called `aspell.exe` if it was found. Git GUI is implemented as a Tcl/Tk script. Due to the unfortunate design of Tcl on Windows, the search path when looking for an executable _always includes the current directory_. Therefore, malicious repositories can ship with an `aspell.exe` in their top-level directory which is executed by Git GUI without giving the user a chance to inspect it first, i.e. running untrusted code. This issue has been addressed in version 2.39.1. Users are advised to upgrade. Users unable to upgrade should avoid using Git GUI for cloning. If that is not a viable option, at least avoid cloning from untrusted sources.

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

The underlying weakness: Untrusted Search Path

The product searches for critical resources using an externally-supplied search path that can point to resources that are not under the product's direct control.

How developers prevent this class of flaw

  • Hard-code the search path to a set of known-safe values (such as system directories), or only allow them to be specified by the administrator in a configuration file. Do not allow these settings to be modified by an external party. Be careful to avoid related weaknesses such as CWE-426 and CWE-428.
  • When invoking other programs, specify those programs using fully-qualified pathnames. While this is an effective approach, code that uses fully-qualified pathnames might not be portable to other systems that do not use the same pathnames. The portability can be improved by locating the full-qualified paths in a centralized, easily-modifiable location within the source code, and having the code refer to these paths.
  • Remove or restrict all environment settings before invoking other programs. This includes the PATH environment variable, LD_LIBRARY_PATH, and other settings that identify the location of code libraries, and any application-specific search paths.

More Untrusted Search Path vulnerabilities (CWE-426)

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

Third-party and government advisories

Other vulnerabilities in git

All git vulnerabilities

Recent Untrusted Search Path vulnerabilities

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