CVE-2021-30483: isomorphic-git directory traversal via malicious file paths

CVE-2021-30483 · Severity: low · CVSS 3.1 · Published 2021-09-02

isomorphic-git is a JavaScript library that allows developers to work with Git repositories in the browser and Node.js environments. A directory traversal vulnerability allows attackers to write files outside the intended repository directory by crafting a malicious Git repository with specially crafted file paths. This could lead to unauthorized file creation or modification on the system running the application.

Technologies: isomorphic-git (npm). Vendors: npm.

Quick answers

Is CVE-2021-30483 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2021-30483 being exploited in the wild.
How severe is CVE-2021-30483?
Low severity, with a CVSS score of 3.1, published 2 September 2021.
Which products and versions are affected?
isomorphic-git (npm) SEMVER:introduced=0,fixed=1.8.2.
Is there a fix for CVE-2021-30483?
Yes. isomorphic-git (npm): upgrade to 1.8.2 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2021-30483 attacked?
It is attacked over the network, in a software library.
Am I affected by CVE-2021-30483?
Check whether you run isomorphic-git (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • isomorphic-git (npm): upgrade to 1.8.2 or later
    npm install isomorphic-git@1.8.2

Technical details

isomorphic-git before version 1.8.2 is vulnerable to directory traversal (CWE-22) through malicious file paths embedded in a Git repository structure. The vulnerability occurs in the checkout functionality when parsing Git trees without sufficient validation of file paths, allowing use of path traversal sequences (e.g., "../"). An attacker can craft a malicious repository that, when checked out by a victim application, writes files to arbitrary locations on the filesystem. The fix, merged in PR #1339, introduces an UnsafeFilepathError that is thrown when detecting malicious paths during Git tree parsing. The vulnerability requires the victim to clone or checkout a malicious repository but does not require authentication or user interaction beyond the checkout operation itself.

Affected products

  • isomorphic-git isomorphic-git before 1.8.2

Identifiers

  • CVE-2021-30483
  • GHSA-fgxq-p49f-qw99

Timeline

  • 2021-07-30: disclosed
  • 2021-09-02: advisory
  • 2021-04-12: patched: PR #1339 merged with fix

References

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