Rule: -- Sid: 2120 -- Summary: This event is generated when a remote user uses the IMAP CREATE command to send a suspiciously long string to port 143 on an internal server. This may indicate an attempt to exploit a buffer overflow vulnerability in the IMAP CREATE command in the Alt-N MDaemon IMAP server. This may also affect other IMAP implementations. -- Impact: Remote execution of arbitrary code, which could allow an attacker to interfere with or crash mail services. The attacker must have a valid IMAP account and must be authenticated by the mail server to attempt this exploit. -- Detailed Information: This event may indicate an attempt to exploit a buffer overflow vulnerability in the Alt-N MDaemon IMAP server CREATE command. If an authenticated user creates a folder with a sufficiently long name on the Alt-N MDaemon IMAP server, arbitrary commands can be executed with system privileges. -- Affected Systems: Alt-N MDaemon 6.7.5 or Alt-N MDaemon 6.7.9 IMAP servers. -- Attack Scenarios: An authenticated user can create a new folder with a sufficiently long name, creating a buffer overflow condition. The attacker can then execute arbitrary code with system privileges, which may allow the attacker to interfere with or crash mail services. -- Ease of Attack: Exploits exist, but the user must have an account and be authenticated before attempting the exploit. -- False Positives: None known. -- False Negatives: None known. -- Corrective Action: Upgrade to the latest non-affected version of the software. Apply the appropriate vendor supplied patches. Check the host for signs of compromise. -- Contributors: Sourcefire Vulnerability Research Team Brian Caswell Sourcefire Technical Publications Team Jen Harvey -- Additional References: Nessus http://cgi.nessus.org/plugins/dump.php3?id=11577 --