[Snort-sigs] SID 1359
anton at ...1177...
Thu Apr 17 15:19:04 EDT 2003
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# $Id: snort-sid-1359.txt,v 1.1 2003/02/18 22:31:30 anton Exp anton $
Rule: alert tcp $EXTERNAL_NET any -> $HTTP_SERVERS $HTTP_PORTS
(msg:"WEB-ATTACKS ping command attempt"; flow:to_server,established;
Summary: A web command execution attack involving the use of a
Impact: attacker might have gained an ability to execute system commands
remotely on the system
Detailed Information: This signature triggers when a "ping"
command is used over a plain-text (unencrypted) connection on one of
the specified web ports to the target web server. The "ping"
command may be used to perform information gathering activities. The
signature looks for the "ping" command in the client to web
server network traffic and does not indicate whether the command was
actually successful. The presence of the "ping" command in the
URL indicates that an attacker attempted to trick the web server into
executing system in non-interactive mode i.e. without a valid shell
session. Another case when this signature might trigger is unencrypted
HTTP tunneling connection to the server or a shell connection through
an exploit of the web server.
Attack Scenarios: An attacker uses a "ping" command to
perform anonymous reconnaissance
Ease of Attack: very easy, no exploit software required
False Positives: none known
False Negatives: none known
Corrective Action: check the web server software for vulnerabilities
and possible upgrade the system to the latest version, also
investigate the server for signs of compromise
Contributors: Anton Chuvakin <http://www.chuvakin.org>
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