CVE-2019-1686: A vulnerability in the TCP flags inspection feature for access control lists (ACLs) on Cisco ASR 9000 Series Aggregation Services Routers could allow an…

high8.6CVSS 3.1

AVNACLPRNUINSCCNIHAN

A vulnerability in the TCP flags inspection feature for access control lists (ACLs) on Cisco ASR 9000 Series Aggregation Services Routers could allow an unauthenticated, remote attacker to bypass protection offered by a configured ACL on an affected device. The vulnerability is due to incorrect processing of the ACL applied to an interface of an affected device when Cisco Express Forwarding load balancing using the 3-tuple hash algorithm is enabled. An attacker could exploit this vulnerability by sending traffic through an affected device that should otherwise be denied by the configured ACL. An exploit could allow the attacker to bypass protection offered by a configured ACL on the affected device. There are workarounds that address this vulnerability. Affected Cisco IOS XR versions are: Cisco IOS XR Software Release 5.1.1 and later till first fixed. First Fixed Releases: 6.5.2 and later, 6.6.1 and later.

Affected

5 ranges

Vendor	Product	Version range	Fixed in
cisco	asr_9000_series_aggregation_services_routers_acl	—	—
cisco	cisco_ios_xr_software	>= unspecified < 6.5.2	6.5.2
cisco	cisco_ios_xr_software	>= unspecified < 6.6.1	6.6.1
cisco	ios_xr	>= 5.1.1 < 6.5.2	6.5.2
cisco	ios_xr	>= 6.5.3 < 6.6.1	6.6.1