CVE-2020-28200 log

Severity Medium
Remote Yes
Type Denial of service
A security issue has been found in Pigeonhole before version 0.5.15. The Sieve interpreter is not protected against abusive scripts that claim excessive resource usage, especially scripts using massive amounts of regexps. This means an attacker can cause a denial of service of the mail delivery system by using excessive amount of CPU and/or reaching the lmtp/lda process limits.
Group Package Affected Fixed Severity Status Ticket
AVG-2088 pigeonhole 0.5.14-1 0.5.15-1 Medium Fixed
Date Advisory Group Package Severity Type
22 Jun 2021 ASA-202106-57 AVG-2088 pigeonhole Medium denial of service

Disabling the regex sieve extension avoids the worst problems. lmtp_user_concurrency_limit may also be helpful.