Rule:

--
Sid:
2106

--
Summary:
This event is generated when a remote user sends an IMAP LSUB command with invalid data to port 143 on an internal server. This may indicate an attempt to exploit a buffer overflow vulnerability in the IMAP LSUB command. This vulnerability may affect other IMAP implementations.

--
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 a large amount of data is sent to a vulnerable IMAP server in the LSUB command, a buffer overflow condition may occur. This can allow the attacker to access the shell, where arbitrary code can be executed. Note that this exploit can only be attempted by a user with a valid IMAP account.

--
Affected Systems:
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:
Upgrade to the latest non-affected version of the software.

Apply the appropriate patches for your operating system.

Check the host for signs of compromise.

--
Contributors:
Sourcefire Vulneratility Research Team
Brian Caswell <bmc@sourcefire.com>
Sourcefire Technical Publications Team
Jen Harvey <jennifer.harvey@sourcefire.com>

--
Additional References:

CVE
http://cve.mitre.org/cgi-bin/cvekey.cgi?keyword=CVE-2000-0284 

Nessus
http://cgi.nessus.org/plugins/dump.php3?id=10374

--
