Software Engineering Institute

Ethereal is a network traffic analysis package. It includes the ability to decode packets containing UCP data. There are three buffer overflow vulnerabilities in the way the UCP protocol dissector decodes packets containing UCP data. These vulnerabilities could be exploited by a remote, unauthenticated attacker by sending a specially crafted UCP packet containing an overly long string, integer, or time field value. Exploitation of these vulnerabilities could result in arbitrary code execution.

According to the e-matters Security Advisory:

To exploit this vulnerability over the wire an attacker must be able to fit more than BUFSIZ bytes into one TCP packet. This means it is only exploitable on the wire if the system has a MTU bigger than BUFSIZ. BUFSIZ is 8192 on glibc systems, 1024 on BSD systems and 512 on Windows systems.

A remote, unauthenticated attacker could execute arbitrary code on the vulnerable system.

Upgrade

Upgrade to version 0.10.3 or later.

Note: Ethereal is considered BETA software at this time.

Disable Dissector

If you are unable to upgrade to version 0.10.3 or later, you can disable the UCP protocol dissector by performing the following actions in Ethereal:

(for Ethereal versions 0.9.x)
1) Select Edit->Protocols
2) Deselect the UCP protocol dissector from the list

(for Ethereal versions 0.10.x)
1) Select Analyze->Enabled Protocols
2) Disable the UCP protocol dissector from the list by unchecking its "Status" checkbox