CVE-2019-1686: medium-severity vulnerability in Cisco IOS XR Software
Cisco ASR 9000 Series Aggregation Services Routers ACL Bypass Vulnerability
Published · Updated
E-mail alert when it lands in KEV, gets a public PoC or its score goes up.
13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 5.8epss 1.6%
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.
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
Affected products
Cisco · Cisco IOS XR SoftwareRelated CVEs — Cisco IOS XR Software
In the same product, most dangerous first.
CVE-2020-3118HIGHCisco IOS XR Software Cisco Discovery Protocol Format String VulnerabilityEPSS 11.7%KEVCVE-2022-20821MEDIUMCisco IOS XR Software Health Check Open Port VulnerabilityEPSS 11.5%KEVCVE-2020-3566HIGHCisco IOS XR Software DVMRP Memory Exhaustion VulnerabilityEPSS 3.7%KEVCVE-2020-3569HIGHCisco IOS XR Software DVMRP Memory Exhaustion VulnerabilitiesEPSS 3.3%KEVCVE-2025-20363CRITICALCVE-2025-20363EPSS 7.2%CVE-2020-3284HIGHCisco IOS XR Software Enhanced Preboot eXecution Environment Unsigned Code Execution VulnerabilityEPSS 2.9%