CVE-2021-21300

Name
CVE-2021-21300
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.
NVD Severity
medium
Other trackers
Mailing lists
Exploits
Forges
GitHub (code, issues), Aports (code, issues)

References

Type URI
Patch https://github.com/git/git/commit/684dd4c2b414bcf648505e74498a608f28de4592
Vendor Advisory https://git-scm.com/docs/gitattributes#_filter
Third Party Advisory https://github.com/git/git/security/advisories/GHSA-8prw-h3cq-mghm
Release Notes https://lore.kernel.org/git/xmqqim6019yd.fsf@gitster.c.googlers.com/
Vendor Advisory https://git-scm.com/docs/git-config#Documentation/git-config.txt-coresymlinks
Exploit http://www.openwall.com/lists/oss-security/2021/03/09/3
Third Party Advisory https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/LCLJJLKKMS5WRFO6C475AOUZTWQLIARX/
Mailing List https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/LMXX2POK5X576BSDWSXGU7EIK6I72ERU/
Mailing List https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/BBPNGLQSYJHLZZ37BO42YY6S5OTIF4L4/
Third Party Advisory https://support.apple.com/kb/HT212320
Mailing List http://seclists.org/fulldisclosure/2021/Apr/60
Third Party Advisory https://security.gentoo.org/glsa/202104-01
Exploit http://packetstormsecurity.com/files/163978/Git-LFS-Clone-Command-Execution.html

Match rules

CPE URI Source package Min version Max version
cpe:2.3:a:git-scm:git:*:*:*:*:*:*:*:* git >= None <= 2.14.2
cpe:2.3:a:git-scm:git:*:*:*:*:*:*:*:* git >= 2.17.0 < 2.17.6
cpe:2.3:a:git-scm:git:*:*:*:*:*:*:*:* git >= 2.18.0 < 2.18.5
cpe:2.3:a:git-scm:git:*:*:*:*:*:*:*:* git >= 2.19.0 < 2.19.6
cpe:2.3:a:git-scm:git:*:*:*:*:*:*:*:* git >= 2.20.0 < 2.20.5
cpe:2.3:a:git-scm:git:*:*:*:*:*:*:*:* git >= 2.21.0 < 2.21.4
cpe:2.3:a:git-scm:git:*:*:*:*:*:*:*:* git >= 2.22.0 < 2.22.5
cpe:2.3:a:git-scm:git:*:*:*:*:*:*:*:* git >= 2.23.0 < 2.23.4
cpe:2.3:a:git-scm:git:*:*:*:*:*:*:*:* git >= 2.24.0 < 2.24.4
cpe:2.3:a:git-scm:git:*:*:*:*:*:*:*:* git >= 2.25.0 < 2.25.5
cpe:2.3:a:git-scm:git:*:*:*:*:*:*:*:* git >= 2.26.0 < 2.26.3
cpe:2.3:a:git-scm:git:2.27.0:*:*:*:*:*:*:* git == None == 2.27.0
cpe:2.3:a:git-scm:git:2.28.0:*:*:*:*:*:*:* git == None == 2.28.0
cpe:2.3:a:git-scm:git:*:*:*:*:*:*:*:* git >= 2.29.0 < 2.29.3
cpe:2.3:a:git-scm:git:*:*:*:*:*:*:*:* git >= 2.30.0 < 2.30.2

Vulnerable and fixed packages

Source package Branch Version Maintainer Status
git 3.13-main 2.30.2-r0 Natanael Copa <ncopa@alpinelinux.org> fixed
git 3.12-main 2.26.3-r0 Natanael Copa <ncopa@alpinelinux.org> fixed
git 3.10-main 2.22.5-r0 Natanael Copa <ncopa@alpinelinux.org> fixed
git 3.11-main 2.24.4-r0 Natanael Copa <ncopa@alpinelinux.org> fixed