Rule: -- Sid: 1885 -- Summary: This rule has been placed in deleted.rules -- Impact: attacker might have gained an ability to execute commands remotely on the system. -- Detailed Information: This signature triggers when a UNIX "id" command is used to confirm the user name of the currently logged in user over any unencrypted connection. Such connection can be either a legitimate telnet connection or a result of spawning a shell on FTP, POP3, SMTP or other port as a consequence of network exploit. The string "uid=" and "(http)" is an output of an "id" command indicating that the user has "http" account privileges, typically used by the web server process. Seeing such a response indicates that some user connected over the network to a target web server and likely exploited the web server to launch a shell. -- Affected Systems: -- Attack Scenarios: a buffer overflow exploit against the WWW server results in "/bin/sh" being executed. An automated script performing an attack, checks for the success of the exploit via an "id" command. -- Ease of Attack: this post-attack behavior can accompany different attacks -- False Positives: None Known the signature will trigger if a legitimate system administrator executes the "id" command over the telnet connection which uses one of the web ports, as defined in snort.conf -- False Negatives: not known -- Corrective Action: investigate the server for signs of compromise, run the integrity checking software, look for other IDS alerts involving the same IP addresses. -- Contributors: Anton Chuvakin -- Additional References: --