SourceTree for Windows - Remote Code Injection using Git LFS - CVE-2020-27955 & CVE-2021-21237

脆弱性の概要

This advisory discloses a critical severity security vulnerability which was introduced through the git-lfs library and discovered in version 3.3.9 of SourceTree for Windows. Both CVE-2020-27955 & CVE-2021-21237 refer to the same underlying vulnerability, Remote Code Injection using Git LFS. Versions of SourceTree for Windows starting with 0.9.4 before 3.4.3 (the fixed version for CVE-2020-27955 and CVE-2021-21237) are affected by this vulnerability.

Remote Code Injection using Git LFS - CVE-2020-27955 & CVE-2021-21237

深刻度

Atlassian rates the severity level of this vulnerability as critical, according to the scale published in our Atlassian severity levels. The scale allows us to rank the severity as critical, high, moderate or low.

This is our assessment and you should evaluate its applicability to your own IT environment.

説明

Vulnerability occurs when a user clones a malicious repository and tries to enable Git LFS to the repository

1. Clone the repository

2. Go to the Repository Tab -> Git LFS -> Start Repo

Loading a malicious repository will allow an attacker to execute arbitrary commands on the system.

All versions of SourceTree for Windows up to and including 3.4.2 are affected by this vulnerability.

この問題はこちらで追跡できます。

SRCTREEWIN-13410 - RCE via git-lfs in Sourcetree for Windows - CVE-2020-27955 CLOSED

SRCTREEWIN-13480 - RCE via git-lfs in Sourcetree for Windows - CVE-2021-21237 CLOSED

Vulnerability References

• CVE-2020-27955 advisory from Github: https://github.com/git-lfs/git-lfs/security/advisories/GHSA-4g4p-42wc-9f3m

• CVE-2021-21237 advisory from Github: https://github.com/git-lfs/git-lfs/security/advisories/GHSA-cx3w-xqmc-84g5

• Original advisory by Dawid Golunski: https://legalhackers.com/advisories/Git-LFS-RCE-Exploit-CVE-2020-27955.html

修正

弊社ではこの問題に対応するために次の対応を行いました。

1. Released version 3.4.3 that contains a fix for this issue.

必要なアクション

Atlassian recommends that you upgrade to the latest version. For a full description of the latest version of SourceTree for Windows, see the release notes. Download the latest version of the standard installer or the enterprise installer.

Upgrade to version 3.4.3 or higher.

問題の軽減策

• Update git and git-lfs on your system to the latest versions and use them in your existing Sourcetree.

サポート

If you did not receive an email for this advisory and you wish to receive such emails in the future go to https://my.atlassian.com/email and subscribe to Alerts emails.
If you have questions or concerns regarding this advisory, please raise a support request at https://support.atlassian.com/ja/.

参考