CVE-2021-21300
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
- 8.0Highscored by the publisher (CNA)
- Exploited in the wild
- Not knownPublic exploit code; not in CISA KEV
- EPSS
- 88.5%chance of exploitation in the next 30 daystop 0.3% of scored CVEsFIRST score of 11 Nov 2026
- Fix
- Patch availablesee the advisories in the references
- Published
- 9 Mar 2021analysed here 12 Nov 2026
Summary
Triage
The summary, impact and action text on this page are written by our AI analysis pipeline, or taken from the NVD description when a CVE was imported from NVD. They are not the vendor's wording: check them against the sources. A longer AI executive summary and technical analysis are generated for signed-in accounts on the Max plan.
Affected products
| Product | Affected versions | Vendor says fixed in |
|---|---|---|
| git | >= 2.14.2 and < 2.17.62.17.6>= 2.18.0 and < 2.18.5>= 2.19.0 and < 2.19.6>= 2.20.0 and < 2.20.5>= 2.21.0 and < 2.21.4>= 2.22.0 and < 2.22.5>= 2.23.0 and < 2.23.4>= 2.24.0 and < 2.24.4>= 2.25.0 and < 2.25.5>= 2.26.0 and < 2.26.3>= 2.27.0 and < 2.27.1>= 2.28.0 and < 2.28.1>= 2.29.0 and < 2.29.3>= 2.30.0 and < 2.30.1Vendor says fixed in: not stated |
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.
Products named in our analysis
- git-scm:git
- fedoraproject:fedora
- apple:xcode
- debian:debian_linux
Fix and mitigation
WAF and other mitigations
Can a WAF block it? Partly. The bug can be reached over the network, so generic WAF rules may stop some attacks. Its weakness type is unknown, so we cannot be more precise.
Also consider: patch
Based on the weakness type only; no CVE-specific evidence yet. We check Cloudflare, AWS, Google Cloud Armor and Azure; for Akamai, Imperva, Fastly, F5, ask your vendor.
Remediation steps (AI-written)
Step-by-step remediation is generated for accounts on the Max plan, for CVEs that match a technology in their stack. Add this technology to your stack to see the fix checklist.
Exploitation evidence
- CISA KEV catalog
- Not listed as of our last sync.
- Public exploit code
- Yes: 1 Metasploit module · 14 GitHub proofs of concept
Metasploit
- exploit/multi/http/git_lfs_clone_command_execexploit, rank excellent
GitHub proofs of concept
- Maskhe/CVE-2021-213001 stars
- AlkenePan/CVE-2021-213000 stars
- Faisal78123/CVE-2021-213000 stars
- erranfenech/CVE-2021-213000 stars
and 10 more repositories
Listed so you can judge urgency, not as a recommendation to run anything. GitHub “proofs of concept” are unvetted: some are fake or carry malware. Exploit-DB marks the entries its staff verified.
Timeline
- 9 Mar 2021Published
- 10 Mar 2021First public exploit or proof of conceptsame day later
- 3 Aug 2024CVE record last updated1,243 days (about 3 years) later
- 12 Nov 2026Analysed by vulneraibility.com831 days (about 2 years) later
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:N
| Metric | Value | What it means |
|---|---|---|
| Attack vector | NetworkReachable over the internet or any routable network. | Reachable over the internet or any routable network. |
| Attack complexity | HighNeeds specific conditions, a race or a particular configuration. | Needs specific conditions, a race or a particular configuration. |
| Privileges required | NoneThe attacker needs no prior access. | The attacker needs no prior access. |
| User interaction | RequiredA victim must click, open or otherwise cooperate. | A victim must click, open or otherwise cooperate. |
| Scope | ChangedImpact crosses a security boundary into other components. | Impact crosses a security boundary into other components. |
| Confidentiality | HighTotal data disclosure possible. | Total data disclosure possible. |
| Integrity | HighComplete modification possible. | Complete modification possible. |
| Availability | NoneThe service stays up. | The service stays up. |
Common questions
Is CVE-2021-21300 being exploited?
Not confirmed. CVE-2021-21300 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 89% probability of exploitation in the next 30 days.
How severe is CVE-2021-21300?
CVE-2021-21300 is rated High with a CVSS score of 8.0. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2021-21300?
Yes. A fix has been recorded for CVE-2021-21300. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2021-21300 affect?
CVE-2021-21300 affects git-scm:git, fedoraproject:fedora, apple:xcode, debian:debian_linux. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
References
14 references in the CVE record, grouped by the tags the record gives them.
Advisories (4)
- lists.fedoraproject.org /archives/list/package-announce%40lists.fedoraproject.org/message/LCLJJLKKMS5WRF
- lists.fedoraproject.org /archives/list/package-announce%40lists.fedoraproject.org/message/LMXX2POK5X576B
- lists.fedoraproject.org /archives/list/package-announce%40lists.fedoraproject.org/message/BBPNGLQSYJHLZZ
- security.gentoo.org /glsa/202104-01
Other links (10)
- github.com /git/git/security/advisories/GHSA-8prw-h3cq-mghm
- lore.kernel.org /git/xmqqim6019yd.fsf%40gitster.c.googlers.com/
- git-scm.com /docs/git-config#Documentation/git-config.txt-coresymlinks
- git-scm.com /docs/gitattributes#_filter
- github.com /git/git/commit/684dd4c2b414bcf648505e74498a608f28de4592
- openwall.com /lists/oss-security/2021/03/09/3
Show 4 more
- support.apple.com /kb/HT212320
- seclists.org /fulldisclosure/2021/Apr/60
- packetstormsecurity.com /files/163978/Git-LFS-Clone-Command-Execution.html
- lists.debian.org /debian-lts-announce/2022/10/msg00014.html
Where the data on this page comes from
- CVE List (CVE.org): description, affected versions, references; CVE Terms of Use
- NVD: CVSS and CPE data
- FIRST EPSS: exploit probability and percentile
- Metasploit Framework: exploit and scanner modules
- PoC-in-GitHub: GitHub repositories that claim a proof of concept
Summary, impact and triage tags: written by our AI analysis pipeline from the sources above. Check them against the sources.
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