CVE-2024-35179

Stalwart Mail Server is an open-source mail server. Prior to version 0.8.0, when using RUN_AS_USER, the specified user (and therefore, web interface admins) can read arbitrary files as root. This issue affects admins who have set up to run stalwart with RUN_AS_USER who handed out admin credentials to the mail server but expect these to only grant access according to the RUN_AS_USER and are attacked where the attackers managed to achieve Arbitrary Code Execution using another vulnerability. Version 0.8.0 contains a patch for the issue.

Weakness

The product does not drop privileges before passing control of a resource to an actor that does not have those privileges.

Potential Mitigations

• Compartmentalize the system to have “safe” areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area.
• Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.

References

• https://github.com/stalwartlabs/mail-server/security/advisories/GHSA-5pfx-j27j-4c6h
• https://github.com/stalwartlabs/mail-server/security/advisories/GHSA-5pfx-j27j-4c6h