Use of a Key Past its Expiration Date and Insufficient Session Expiration in Maddy Mail Server

Impact

Any configuration on any maddy version <0.5.4 using auth.pam is affected.

No password expiry or account expiry checking is done when authenticating using PAM.

Patches

Patch is available as part of the 0.5.4 release.

Workarounds

If /etc/shadow authentication is used, it is possible to replace auth.pam with auth.shadow which is not affected.

It is possible to blacklist expired accounts via existing filtering mechanisms (e.g. auth_map to invalid accounts in storage.imapsql).

References

• https://github.com/foxcpp/maddy/blob/3412e59a2c92106e194fa69f2f1017c020037c9c/internal/auth/pam/pam.c
• https://linux.die.net/man/3/pam_acct_mgmt

For more information

If you have any questions or comments about this advisory:

• Open an issue in https://github.com/foxcpp/maddy
• Email [email protected]