Attacker Value
Moderate
(1 user assessed)
Exploitability
Moderate
(1 user assessed)
User Interaction
Required
Privileges Required
None
Attack Vector
Network
4

CVE-2021-21300

Disclosure Date: March 09, 2021
Add MITRE ATT&CK tactics and techniques that apply to this CVE.

Description

Git is an open-source distributed revision control system. In affected versions of Git a specially crafted repository that contains symbolic links as well as files using a clean/smudge filter such as Git LFS, may cause just-checked out script to be executed while cloning onto a case-insensitive file system such as NTFS, HFS+ or APFS (i.e. the default file systems on Windows and macOS). Note that clean/smudge filters have to be configured for that. Git for Windows configures Git LFS by default, and is therefore vulnerable. The problem has been patched in the versions published on Tuesday, March 9th, 2021. As a workaound, if symbolic link support is disabled in Git (e.g. via git config --global core.symlinks false), the described attack won’t work. Likewise, if no clean/smudge filters such as Git LFS are configured globally (i.e. before cloning), the attack is foiled. As always, it is best to avoid cloning repositories from untrusted sources. The earliest impacted version is 2.14.2. The fix versions are: 2.30.1, 2.29.3, 2.28.1, 2.27.1, 2.26.3, 2.25.5, 2.24.4, 2.23.4, 2.22.5, 2.21.4, 2.20.5, 2.19.6, 2.18.5, 2.17.62.17.6.

Add Assessment

CVSS V3 Severity and Metrics
Base Score:
7.5 High
Impact Score:
5.9
Exploitability Score:
1.6
Vector:
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
Attack Vector (AV):
Network
Attack Complexity (AC):
High
Privileges Required (PR):
None
User Interaction (UI):
Required
Scope (S):
Unchanged
Confidentiality (C):
High
Integrity (I):
High
Availability (A):
High

General Information

Vendors

  • apple,
  • debian,
  • fedoraproject,
  • git-scm

Products

  • debian linux 10.0,
  • fedora 32,
  • fedora 33,
  • fedora 34,
  • git,
  • git 2.27.0,
  • git 2.28.0,
  • xcode

Additional Info

Technical Analysis