Another Cisco flaw, this time affecting firewalls, has been uncovered at the Black Hat security conference

Craig Matsumoto, Contributor

August 4, 2006

2 Min Read

Cisco Systems Inc. (Nasdaq: CSCO) almost made it through this year's Black Hat Inc. security conference without some major controversy, scandal, or problem. Almost.

In an Aug. 2 presentation on VOIP security, German researcher Hendrik Scholz of Freenet Cityline GmbH -- a unit of Freenet.de AG -- briefly mentioned a security flaw related to Cisco's PIX firewalls. The information reportedly was on Scholz's last slide and didn't include specifics.

A Cisco spokesman says the company has just begun investigating the validity and scope of the flaw. Cisco, applying what the spokesman says is the usual procedure, has handed the problem to its Product Security Incident Response Team ("a Quinn Martin production!").

"They take all of these seriously and look into every one of them," the spokesman says. "That is where we are now. The PSIRT organization is running tests to see if this is a valid claim and what the fixes or workarounds might be."

Cisco has spoken to Scholz, who seems willing to help Cisco out, the spokesman says.

Once Cisco nails down the details of the flaw and determines what software versions it does and doesn't affect, the information will be published in a security alert.

VOIP security is getting a lot of attention, thanks in part to a hacking scheme uncovered in June. (See Two Charged in VOIP Hacking Scandal and Experts: VOIP Attacks Are Tough to Stop.) Scholz's talk was titled, "SIP Stack Fingerprinting and Stack Difference Attacks," but it's not clear whether the PIX flaw he mentioned was directly related to SIP or to VOIP.

Scholz could not immediately be reached for comment.

Last year, Cisco caused a stir at Black Hat for trying to excise researcher Michael Lynn's presentation, in which he said it's possible for a hacker to gain control of a Cisco router. Reports say Cisco and Lynn's employer, IBM Internet Security Systems (ISS), even hired workers to cut Lynn's presentation out of the proceedings books. (See Cisco Faces Security Flap and Cisco Reveals 'Black Hat' Flaw.)

Lynn gave the talk anyway, subsequently quitting his job and enduring a brush with the FBI. Shortly after, he got hired by Juniper Networks Inc. (Nasdaq: JNPR). (See Juniper Hires 'Black Hat' Speaker.)

Black Hat, incidentally, is owned by CMP Media LLC ("a United Business Media plc production!"), which owns Light Reading.

— Craig Matsumoto, Senior Editor, Light Reading

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