Home/CVE/Git is an open-source distributed revision control system. In affected versions of Git a specially crafted repository th
CVE

CVE-2021-21300

Git is an open-source distributed revision control system. In affected versions of Git a specially crafted repository th

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.

HIGH · CVSS 8 EPSS 0.61881
Act now
  • EPSS ≥ 0.50 - high probability of exploitation in the next 30 days
  • EPSS percentile: top 2% of all CVEs by exploitation likelihood
  • Public exploit or PoC is available
  • CVSS base score ≥ 7.0
Sigma rules8 YARA rules0
⬡

Weakness Classification

CWE-59Improper Link Resolution Before File Access ('Link Following')
CWE-59Improper Link Resolution Before File Access ('Link Following')
▤

Affected Products & Versions

17
git-scm git<= 2.14.2
git-scm git>= 2.17.0 and < 2.17.6
git-scm git>= 2.18.0 and < 2.18.5
git-scm git>= 2.19.0 and < 2.19.6
git-scm git>= 2.20.0 and < 2.20.5
git-scm git>= 2.21.0 and < 2.21.4
git-scm git>= 2.22.0 and < 2.22.5
git-scm git>= 2.23.0 and < 2.23.4
⚠

Public Exploits & PoCs

1
pocpacketstormsecurity.com · Git-LFS-Clone-Command-Execution.htmlpacketstormsecurity.com
◈

Sigma Hunt Rules

8
Exact rules name this CVE ID. Product rules name an affected product in their title. Related rules cover techniques used by actors who exploited this CVE. Showing the most relevant matches; the complete related set is on the full drill-down.
producthighSuspicious Microsoft Office Child Process - MacOS
producthighRemote Access Tool - Renamed MeshAgent Execution - MacOS
producthighBinary Padding - MacOS
productmediumSuspicious Execution via macOS Script Editor
productmediumSystem Information Discovery Via Sysctl - MacOS
productmediumNew File Exclusion Added To Time Machine Via Tmutil - MacOS
▣

Scoring & Timeline

8
HIGH · CVSS v3.1 · security-advisories@github.com
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD09 Mar 2021 · 08:15 PM
CVSS VectorCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:N
⚑

Vendor Advisories

9
suse-csafopenSUSE-SU-2024:10786-1
suse-csafopenSUSE-SU-2024:10787-1
suse-csafopenSUSE-SU-2021:2555-1
suse-csafSUSE-SU-2021:2555-1
suse-csafopenSUSE-SU-2021:0405-1
🔗

References & Sources

13
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.
http://seclists.org/fulldisclosure/2021/Apr/60Mailing ListThird Party Advisory
http://www.openwall.com/lists/oss-security/2021/03/09/3ExploitMailing ListThird Party Advisory
https://git-scm.com/docs/git-config#Documentation/git-config.txt-coresymlinksVendor Advisory
https://git-scm.com/docs/gitattributes#_filterVendor Advisory
https://github.com/git/git/commit/684dd4c2b414bcf648505e74498a608f28de4592PatchThird Party Advisory
https://github.com/git/git/security/advisories/GHSA-8prw-h3cq-mghmThird Party Advisory
Intelligence Graph · click any node to traverse
CVETechnique ActorTool Family
drag to reposition · click any node to traverse · button top-right enlarges
External lookups - second-class, for what we don’t hold ourselves
NVDCVE.orgCISAVulnersExploit-DBGitHub PoCVulnCheck KEVGreyNoise
Vulnerabilities
CISA KEV catalog
CWE weaknesses
CAPEC attack patterns
Package vulnerabilities
Threat intelligence
Threat actors
Tools & malware
ATT&CK techniques
IOCs
Detection & defense
Sigma rules
YARA rules
Atomic Red Team tests
D3FEND countermeasures
Compliance
NIST 800-53
ISO 27001:2022
SOC 2 TSC
PCI-DSS v4.0
CIS Controls v8.1
About
All capabilities
Live statistics
Data sources
Privacy policy
Terms of service
threatengine.sh  ·  Open-source threat intelligence platform  ·  100+ authoritative sources  ·  Every fact traces to its origin