CSRF vulnerability in save-server

Impact

Versions prior to version v1.05 are affected by a CSRF vulnerability, as there is no CSRF mitigation (Tokens etc.). The fix introduced in version v1.05 unintentionally breaks uploading so version v1.0.7 is the fixed version.

This is patched by implementing Double submit.

The CSRF attack would require you to navigate to a malicious site while you have an active session with Save-Server (Session key stored in cookies). The malicious user would then be able to perform some actions, including:

• Upload file
• Delete file
• Add redirect

If you are logged in as root, this attack is significantly more severe. They can (in addition to the above):

• Create users
• Delete users
• Update users (change password)

If they updated the password of a user, that user's files would then be available. If the root password is updated, all files would be visible if they logged in with the new password.

Note that due to the same origin policy malicious actors cannot view the gallery or the response of any of the methods, nor be sure they succeeded.

Patches

This issue has been patched. Update to version v1.0.7 or above to benefit from this fix.

Workarounds

None. You should upgrade.

References

What is CSRF: https://owasp.org/www-community/attacks/csrf Fix type: https://medium.com/cross-site-request-forgery-csrf/double-submit-cookie-pattern-65bb71d80d9f

For more information

If you have any questions or comments about this advisory:

• Open an issue in Save-server
• Email us at hi@nezto.re
• Join our discord (preferred): Invite