Rule: -- Sid: 1902 -- Summary: This event is generated when a remote attacker sends an IMAP LSUB command with a malformed and overly long argument to an internal IMAP server port. This may indicate an attempt to exploit a buffer overflow vulnerability in the IMAP LSUB command. -- Impact: Possible shell access on the IMAP server, leading to arbitrary code execution. The attacker must have a valid IMAP account on the mail server to attempt this exploit. -- Detailed Information: When an LSUB command with an overly long argument is sent to a vulnerable IMAP server, a buffer overflow condition may occur. This can allow an attacker to execute arbitrary code from the command shell. Note that this exploit can only be attempted by a user with a valid IMAP account. -- Affected Systems: Any operating system running University of Washington imapd versions 10.234 or 12.264. -- Attack Scenarios: An attacker with an IMAP account on the server can send a sufficiently long LSUB command to the IMAP server, creating a buffer overflow condition. This can then allow the attacker to gain shell access on the compromised server, possibly leading to the execution of arbitrary code. -- Ease of Attack: Simple. Exploits exist, but the user must have a valid IMAP account on the server. -- False Positives: None known. -- False Negatives: None known. -- Corrective Action: Apply the patch for your current version of imapd appropriate to your operating system. -- Contributors: Original rule written by Brian Caswell <bmc@sourcefire.com> Sourcefire Research Team Sourcefire Technical Publications Team Jennifer Harvey <jennifer.harvey@sourcefire.com> -- Additional References: Bugtraq http://www.securityfocus.com/bid/1110 --
