# CVE-2020-27955: Git LFS can execute a Git binary from the current directory

> Git LFS allows remote code execution via untrusted repositories, requiring developers to upgrade to a patched version.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 5 Nov 2020
- **Updated:** 4 Aug 2024
- **Also known as:** BIT-git-lfs-2020-27955, GHSA-4g4p-42wc-9f3m

## What is CVE-2020-27955?

CVE-2020-27955 is a critical code injection vulnerability in n/a, published on 5 Nov 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Git LFS 2.12.0 allows Remote Code Execution.

Weakness: CWE-427 (Uncontrolled Search Path Element)

## Which versions are affected by CVE-2020-27955?

3 open source packages ship an affected version, including github.com/git-lfs/git-lfs and git-lfs. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/git-lfs/git-lfs` | Go | All versions | 2.12.1 |
| `github.com/git-lfs/git-lfs` | Go | All versions | 2.12.1 |
| `git-lfs` | Bitnami | From 2.12.0 | 2.12.1 |

Products: Git Large File Storage Project Git Large File Storage.

## How do I fix CVE-2020-27955?

Upgrade github.com/git-lfs/git-lfs to 2.12.1 or later.

## Is CVE-2020-27955 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2020-27955 exists.

Public exploit code:

- Git-lfs RCE exploit CVE-2020-27955 - tested on Windows on: git, gh cli, GitHub Desktop, Visual Studio, SourceTree etc. (github_poc): https://github.com/ExploitBox/git-lfs-RCE-exploit-CVE-2020-27955
- https://github.com/r00t4dm/CVE-2020-27955 (github_poc): https://github.com/r00t4dm/CVE-2020-27955
- https://github.com/ExploitBox/git-lfs-RCE-exploit-CVE-2020-27955-Go (github_poc): https://github.com/ExploitBox/git-lfs-RCE-exploit-CVE-2020-27955-Go
- cve-2020-27955 (github_poc): https://github.com/TheTh1nk3r/cve-2020-27955
- https://github.com/DeeLMind/CVE-2020-27955-LFS (github_poc): https://github.com/DeeLMind/CVE-2020-27955-LFS
- Git Remote Code Execution via git-lfs (CVE-2020-27955) (metasploit)

## Other vulnerabilities in n/a

- [CVE-2022-24826](https://insights.sbomify.com/CVE-2022-24826/): Git LFS can execute a binary from the current directory on Windows (critical 9.8)
- [CVE-2017-17831](https://insights.sbomify.com/CVE-2017-17831/): GitHub Git LFS Arbitrary command execution vulnerability (high 8.8)
- [CVE-2021-21237](https://insights.sbomify.com/CVE-2021-21237/): Git LFS can execute a Git binary from the current directory on Windows (high 7.2)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-27955 and fix it if it is affected.

What it is: CVE-2020-27955 is a critical code injection vulnerability in n/a, published on 5 Nov 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2020-27955 exists.

Affected packages and fixed versions:
- github.com/git-lfs/git-lfs (Go): affected all versions; fixed in 2.12.1
- github.com/git-lfs/git-lfs (Go): affected all versions; fixed in 2.12.1
- git-lfs (Bitnami): affected from 2.12.0; fixed in 2.12.1

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2020-27955/ (Markdown: https://insights.sbomify.com/CVE-2020-27955/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-27955
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-27955
- OSV: https://osv.dev/vulnerability/CVE-2020-27955

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-27955/
Summaries are generated and may contain mistakes; the official description above is the record.