Cyrus IMAP < 3.0.16, 3.2.x < 3.2.8, 3.4.x < 3.4.2 DoS Vulnerability

Cyrus IMAP is prone to a denial of service (DoS) vulnerability.

Certain user inputs are used as hash table keys during processing. A poorly chosen string hashing algorithm meant that the user could control which bucket their data was stored in, allowing a malicious user to direct many inputs to a single bucket. Each subsequent insertion to the same bucket requires a strcmp of every other entry in it. At tens of thousands of entries, each new insertion could keep the CPU busy in a strcmp loop for minutes.

Cyrus IMAP prior to version 3.0.16, version 3.2.x through 3.2.7 and 3.4.x through 3.4.1.

Checks if a vulnerable version is present on the target host.

Update to version 3.0.16, 3.2.8, 3.4.2 or later.