CVE-2021-21300highCWE-59

CVE-2021-21300: high-severity vulnerability in git

malicious repositories can execute remote code while cloning

Published · Updated

58Vexday Risk Score

Patch soon. It has a working public exploit.

ssvc Attendcvss 8epss 89%
from disclosure to weapon48 days
Published on NVDMar 9
metasploit+48d
exploitation probability
89%top 1% of all CVEs
observed exploitation
nono source reports it
What the vendors declare (VEX)

Official vendor statements in CSAF/VEX format: whether their product is affected, already fixed, or ruled out — and why. These are the vendor's assertions, not Vexday's judgment.

Red HatVEX document ↗
Affected
3 products (67 components)
Red Hat Software Collections · Red Hat Enterprise Linux 7 · Red Hat Enterprise Linux 6
workaround: 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…
Not affected
4 products (36 components) — because the vulnerable code is not present in the product
Red Hat Enterprise Linux 8 · Red Hat Enterprise Linux 9 · Red Hat OpenShift Container Platform 3.11 · Red Hat OpenShift Container Platform 4
In short

A malicious Git repository can execute code on your computer when you clone it, if you're using Windows or macOS. This happens because the repository uses tricks with symbolic links and file filters (like Git LFS) to run hidden scripts during the cloning process.

Technical detail

A case-insensitive file system (NTFS, HFS+, APFS) combined with symbolic links and configured clean/smudge filters (e.g., Git LFS) allows a malicious repository to execute arbitrary code during clone operations. The attack exploits path collision between symbolic links and filtered files; pre-conditions include Git LFS or similar filters being configured globally and the target system using a case-insensitive filesystem. Impact is remote code execution with the privileges of the cloning user.

Summary generated and translated by AI from the official 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:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:N
Affected products
git · git
Related CVEs — git

In the same product, most dangerous first.

CVE-2025-48384HIGHGit allows arbitrary code execution through broken config quotingEPSS 4.2%KEVCVE-2022-23521CRITICALgitattributes parsing integer overflow in gitEPSS 56.3%CVE-2023-25652HIGH"git apply --reject" partially-controlled arbitrary file writeEPSS 51.9%CVE-2022-41903CRITICALInteger overflow in `git archive`, `git log --format` leading to RCE in gitEPSS 44.3%CVE-2024-32002CRITICALGit's recursive clones on case-insensitive filesystems that support symlinks are susceptible to Remote Code ExecutionEPSS 29.2%CVE-2020-5260CRITICALmalicious URLs may cause Git to present stored credentials to the wrong serverEPSS 10.0%
References
http://packetstormsecurity.com/files/163978/Git-LFS-Clone-Command-Execution.htmlhttp://seclists.org/fulldisclosure/2021/Apr/60https://github.com/git/git/commit/684dd4c2b414bcf648505e74498a608f28de4592https://github.com/git/git/security/advisories/GHSA-8prw-h3cq-mghmhttps://git-scm.com/docs/gitattributes#_filterhttps://git-scm.com/docs/git-config#Documentation/git-config.txt-coresymlinkshttps://lists.debian.org/debian-lts-announce/2022/10/msg00014.htmlhttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BBPNGLQSYJHLZZ37BO42YY6S5OTIF4L4/https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/LCLJJLKKMS5WRFO6C475AOUZTWQLIARX/https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/LMXX2POK5X576BSDWSXGU7EIK6I72ERU/https://lore.kernel.org/git/xmqqim6019yd.fsf%40gitster.c.googlers.com/https://security.gentoo.org/glsa/202104-01