CVE-2024-23185: open-xchange gmbh ox dovecot pro

Vulnerability summary

CVE-2024-23185 is a high (CVSS 7.5) vulnerability in open-xchange gmbh ox dovecot pro. EPSS estimates a 1.29% chance of exploitation in the next 30 days, higher than 69.9% of scored vulnerabilities.

Timeline

1. 10-09-2024
   PublishedVulnerability first disclosed.
2. 04-11-2025
   Last modifiedVulnerability information updated.

Description

Very large headers can cause resource exhaustion when parsing message. The message-parser normally reads reasonably sized chunks of the message. However, when it feeds them to message-header-parser, it starts building up "full_value" buffer out of the smaller chunks. The full_value buffer has no size limit, so large headers can cause large memory usage. It doesn't matter whether it's a single long header line, or a single header split into multiple lines. This bug exists in all Dovecot versions. Incoming mails typically have some size limits set by MTA, so even largest possible header size may still fit into Dovecot's vsz_limit. So attackers probably can't DoS a victim user this way. A user could APPEND larger mails though, allowing them to DoS themselves (although maybe cause some memory issues for the backend in general). One can implement restrictions on headers on MTA component preceding Dovecot. No publicly available exploits are known.

• CWE-770Allocation of Resources Without Limits or ThrottlingThe product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.