CVE-2019-1686 json
Cisco ASR 9000 Series Aggregation Services Routers ACL Bypass Vulnerability
published 2019-04-17 7 y ago modified 2026-06-17 4 mo ago also EUVD-2019-10243
- cvss
- 5.8
- version 3.0, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 1.6%
- EPSS 1.6% chance of exploitation in 30 days, percentile 75%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- Cisco Cisco IOS XR Software 6.5.2, 6.6.1
CISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 23 mo ago
Exploit prediction
1.59% chance of exploitation in the next 30 days, higher than 75% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.0 | 5.8 | CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N |
| NVD | 3.1 | 8.6 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N |
| NVD | 2.0 | 5.0 | AV:N/AC:L/Au:N/C:N/I:P/A:N |
Affected products
- Cisco Cisco IOS XR Software
Classification
- Weakness
-
- CWE-284 Improper Access Control
- Technology feeds
References
-
tools.cisco.com
/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190417-iosxracl
vendor-advisory
-
securityfocus.com
/bid/108026
vdb-entry, third-party-advisory
Sources
- CVE List CVE-2019-1686
- NVD CVE-2019-1686
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