Vulnerability Note VU#931588

Ethereal is a network traffic analysis package. It includes the ability to decode packets containing BGP data. According to RFC3031, an MPLS label is an identifier used to represent the Forwarding Equivalence Class (FEC) to which that packet is assigned. There is a buffer overflow vulnerability in the way the BGP protocol dissector decodes MPLS IPv6 labels.

According to the e-matters Security Advisory:

When parsing a BGP Packet with a MPLS IPv6 label up to 13 bytes on the stack may be overwritten with arbitrary data. Due to the stacklayout exploitability seems unlikly and was therefore not tested.

A remote, unauthenticated attacker could cause Ethereal to crash or potentially execute code of the attacker's choice.

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 BGP protocol dissector by performing the following actions in Ethereal:

(for Ethereal versions 0.8.x and 0.9.x)

1) Select Edit->Protocols
2) Deselect the BGP protocol dissector from the list

1) Select Analyze->Enabled Protocols
2) Disable the BGP protocol dissector from the list by unchecking its "Status" checkbox