CVE-2021-21300
HighPublic exploitIn 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…
Published Mar 9, 2021 · Updated Aug 7, 2026 · Also known as ALPINE-CVE-2021-21300, DEBIAN-CVE-2021-21300, DLA-3145-1, GHSA-8prw-h3cq-mghm, SUSE-SU-2021:0756-1, SUSE-SU-2021:0757-1, SUSE-SU-2021:2555-1, UBUNTU-CVE-2021-21300, USN-4761-1
Key Facts
Patch immediately- CVE-2021-21300 is a high-severity vulnerability (CVSS 7.5 v3.1) affecting Xcode (Apple), Git (Git-Scm), Debian Linux and 22 more products.
- It is not listed in any known-exploited vulnerabilities catalog. Public exploit code is available.
- EPSS estimates a 89% probability of exploitation in the next 30 days.
- Fixed versions are available, including Xcode 12.5, emacs-git 2.18.5-2.73.amzn1, emacs-git-el 2.18.5-2.73.amzn1.
- Brandefense priority: patch immediately, because it is very likely to be exploited soon.
CVSS v3.1
7.5
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS (30-day exploit likelihood)
89%
Higher than 99.7% of all scored CVEs
Exploited in the wild
No known
Not in a known-exploited catalog
Public exploit code
Available
Proof-of-concept or weaponized module
Get the full CVE-2021-21300 brief as a PDF
Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.
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.
Affected Products
492 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| XcodeApple | See advisory | 12.5 |
| GitGit-Scm | 2.27.0, 2.28.0, >= >= 2.14.2, < 2.17.62.17.6 | 2.14.2 |
| Debian LinuxDebian | 10.0 | n/a |
| FedoraFedoraproject | 32, 33, 34 | n/a |
| rootio-gitrootio | See advisory | 1:2.30.2-1 |
Patched Releases
Xcode
12.5
emacs-git
2.18.5-2.73.amzn1
emacs-git-el
2.18.5-2.73.amzn1
Git
1:2.17.1-1ubuntu0.8, 1:2.20.1-2+deb10u4, 1:2.25.1-1ubuntu3.1, 1:2.30.2-1, 1:2.7.4-0ubuntu1.10, 2.18.5-2.73.amzn1, 2.22.5-r0, 2.23.3-2.ph1, 2.23.3-2.ph2, 2.23.3-2.ph3, 2.23.4-1.amzn2.0.1, 2.24.4-r0, 2.26.2-27.43.1, 2.26.2-3.31.1, 2.26.2-lp152.2.6.1, 2.26.3-r0, 2.30.0-3.ph4, 2.30.2-1, 2.30.2-r0, 2.31.1-10.3.1, 2.33.0-1.3, 2.43.7-1.ph5, <=2.14.2
git-all
2.18.5-2.73.amzn1, 2.23.4-1.amzn2.0.1
git-annex
8.20210903-1.2
git-annex-bash-completion
8.20210903-1.2
git-arch
2.26.2-27.43.1, 2.26.2-3.31.1, 2.26.2-lp152.2.6.1, 2.31.1-10.3.1, 2.33.0-1.3
git-bzr
2.18.5-2.73.amzn1
git-core
2.18.5-2.73.amzn1, 2.23.4-1.amzn2.0.1, 2.26.2-27.43.1, 2.26.2-3.31.1, 2.26.2-lp152.2.6.1, 2.31.1-10.3.1, 2.33.0-1.3
git-core-doc
2.18.5-2.73.amzn1, 2.23.4-1.amzn2.0.1
git-credential-gnome-keyring
2.26.2-lp152.2.6.1, 2.31.1-10.3.1, 2.33.0-1.3
git-credential-libsecret
2.26.2-lp152.2.6.1, 2.31.1-10.3.1, 2.33.0-1.3
git-cvs
2.18.5-2.73.amzn1, 2.23.4-1.amzn2.0.1, 2.26.2-27.43.1, 2.26.2-3.31.1, 2.26.2-lp152.2.6.1, 2.31.1-10.3.1, 2.33.0-1.3
git-daemon
2.18.5-2.73.amzn1, 2.23.4-1.amzn2.0.1, 2.26.2-27.43.1, 2.26.2-3.31.1, 2.26.2-lp152.2.6.1, 2.31.1-10.3.1, 2.33.0-1.3
git-doc
2.26.2-27.43.1, 2.26.2-3.31.1, 2.26.2-lp152.2.6.1, 2.31.1-10.3.1, 2.33.0-1.3
git-email
2.18.5-2.73.amzn1, 2.23.4-1.amzn2.0.1, 2.26.2-27.43.1, 2.26.2-3.31.1, 2.26.2-lp152.2.6.1, 2.31.1-10.3.1, 2.33.0-1.3
git-extras
2.30.0-3.ph4, 2.43.7-1.ph5
git-gui
2.23.4-1.amzn2.0.1, 2.26.2-27.43.1, 2.26.2-3.31.1, 2.26.2-lp152.2.6.1, 2.31.1-10.3.1, 2.33.0-1.3
git-hg
2.18.5-2.73.amzn1
git-instaweb
2.18.5-2.73.amzn1, 2.23.4-1.amzn2.0.1
git-lang
2.30.0-3.ph4, 2.43.7-1.ph5
git-p4
2.18.5-2.73.amzn1, 2.23.4-1.amzn2.0.1, 2.26.2-lp152.2.6.1, 2.31.1-10.3.1, 2.33.0-1.3
git-subtree
2.18.5-2.73.amzn1, 2.23.4-1.amzn2.0.1
git-svn
2.18.5-2.73.amzn1, 2.23.4-1.amzn2.0.1, 2.26.2-27.43.1, 2.26.2-3.31.1, 2.26.2-lp152.2.6.1, 2.31.1-10.3.1, 2.33.0-1.3
Timeline
Publicly disclosed
Mar 9, 2021
Last updated
Aug 7, 2026
Weakness Type
- CWE-59 Improper Link Resolution Before File Access ('Link Following')
References
- advisoryhttps://bugzilla.suse.com/1168930
- advisoryhttps://bugzilla.suse.com/1183026
- advisoryhttps://bugzilla.suse.com/1183580
- advisory20210427 APPLE-SA-2021-04-26-10 Xcode 12.5
- advisoryhttps://github.com/git/git/security/advisories/GHSA-8prw-h3cq-mghm
FAQ
Common Questions.
Git is an open-source distributed revision control system.
Affected: Xcode (Apple); Git (Git-Scm) versions 2.27.0, 2.28.0, >= >= 2.14.2, < 2.17.62.17.6; Debian Linux versions 10.0, among others. The full list is in the CVE brief.
It is not listed in any known-exploited vulnerabilities catalog.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
Public exploit code is available.
Fixed versions are available, including Xcode 12.5, emacs-git 2.18.5-2.73.amzn1, emacs-git-el 2.18.5-2.73.amzn1.
Brandefense priority: patch immediately, because it is very likely to be exploited soon.
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