Permissions, Privileges, and Access Controls
Cisco IOS before 15.3(2)S allows remote attackers to bypass interface ACL restrictions in opportunistic circumstances by sending IPv6 packets in an unspecified scenario in which expected packet drops do not occur for "a small percentage" of the packets, aka Bug ID CSCty73682.
CWE-264 - Permissions Privileges and Access Controls
CWE 264 (permissions, privileges, and access controls) is not a weakness in and of itself, rather it is a category of weaknesses related to the management of permissions, privileges, and other security features used to perform access control. If not addressed, the weaknesses in this category allow attackers to gain privileges for an unintended sphere of control, access sensitive information, and execute arbitrary commands.