Cisco IOS 12.2(33)sxj9 Bypass a restriction or similar Vulnerability
16 Jun. 2017
Cisco IOS 12.2(33)SXJ9 on Supervisor Engine 32 and 720 modules for 6500 and 7600 devices mishandles certain operators, flags, and keywords in TCAM share ACLs, which allows remote attackers to bypass intended access restrictions by sending packets that should have been recognized by a filter, aka Bug ID CSCuy64806.
A vulnerability in the ternary content addressable memory (TCAM) share access control list (ACL) functionality of Cisco IOS Software running on Supervisor Engine 720 and Supervisor Engine 32 Modules for Cisco Catalyst 6500 Series Switches and Cisco 7600 Series Routers could allow an unauthenticated, remote attacker to bypass access control entries (ACEs) in a port access control list (PACL).
The vulnerability is due to the improper implementation of PACL logic for ACEs that include a greater than operator, a less than operator, a tcp flag, the established keyword, or the range keyword. An attacker could exploit this vulnerability by sending packets that meet one or more filter criteria through an affected device. A successful exploit could allow the attacker to bypass the filters defined in the PACL for a targeted system.