What is CVE-2021-34696?

CVE-2021-34696 is a medium-severity vulnerability in Cisco Asr 902, classified under Improper Access Control. CVSS score: 5.8/10. Published 2021-09-23.

How severe is CVE-2021-34696?

Medium severity. CVSS v3 base score is 5.8 out of 10.

Vulnerability in Cisco Asr 902

CVE-2021-34696

A vulnerability in the access control list (ACL) programming of Cisco ASR 900 and ASR 920 Series Aggregation Services Routers could allow an unauthenticated, remote attacker to bypass a configured ACL. This vulnerability is due to incorrect programming of hardware when an ACL is configured using a method other than the configuration CLI. An attacker could exploit this vulnerability by attempting to send traffic through an affected device. A successful exploit could allow the attacker to bypass an ACL on the affected device.

Published 2021-09-23 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.8 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N.

EPSS exploit prediction

EPSS: 0.010 (61.4th percentile), scored 2026-10-02.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 61st percentile — 61.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.010 · newest: 0.010 · change: 0.000

Affected products

Weakness classification (CWE)

CWE-284 — Improper Access Control

References

tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asr900ac… (vendor-advisory, Vendor Advisory)

Frequently asked questions

What is CVE-2021-34696?: CVE-2021-34696 is a medium-severity vulnerability in Cisco Asr 902, classified under Improper Access Control. CVSS score: 5.8/10. Published 2021-09-23.
How severe is CVE-2021-34696?: Medium severity. CVSS v3 base score is 5.8 out of 10.