Vulnerability 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.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Git-Scm | Git | <= 2.14.2 |
| Fedoraproject | Fedora | 32 |
| Apple | Xcode | < 12.5 |
| Apple | Macos | >= 11.0 |
| Debian | Debian Linux | 10.0 |
Related Weaknesses (CWE)
References
- http://packetstormsecurity.com/files/163978/Git-LFS-Clone-Command-Execution.htmlExploitThird Party AdvisoryVDB Entry
- 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
- https://lists.debian.org/debian-lts-announce/2022/10/msg00014.htmlMailing ListThird Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro
- https://lore.kernel.org/git/xmqqim6019yd.fsf%40gitster.c.googlers.com/
- https://security.gentoo.org/glsa/202104-01Third Party Advisory
- https://support.apple.com/kb/HT212320Third Party Advisory
- http://packetstormsecurity.com/files/163978/Git-LFS-Clone-Command-Execution.htmlExploitThird Party AdvisoryVDB Entry
FAQ
What is CVE-2021-21300?
CVE-2021-21300 is a vulnerability with a CVSS score of 8.0 (HIGH). 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 ...
How severe is CVE-2021-21300?
CVE-2021-21300 has been rated HIGH with a CVSS base score of 8.0/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2021-21300?
Check the references section above for vendor advisories and patch information. Affected products include: Git-Scm Git, Fedoraproject Fedora, Apple Xcode, Apple Macos, Debian Debian Linux.