CVE-2023-28979: Junos OS: In a 6PE scenario upon receipt of a specific IPv6 packet an integrity check fails

Severity: medium (CVSS 4.7 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2023-04-17 · updated 2026-06-17
Weakness: CWE-754

Description

An Improper Check for Unusual or Exceptional Conditions vulnerability in the kernel of Juniper Networks Junos OS allows an adjacent unauthenticated attacker to bypass an integrity check. In a 6PE scenario and if an additional integrity check is configured, it will fail to drop specific malformed IPv6 packets, and then these packets will be forwarded to other connected networks. This issue affects Juniper Networks Junos OS: All versions prior to 19.3R3-S7; 19.4 versions prior to 19.4R3-S9; 20.2 versions prior to 20.2R3-S7; 20.3 versions prior to 20.3R3-S5; 20.4 versions prior to 20.4R3-S4; 21.1 versions prior to 21.1R3-S3; 21.2 versions prior to 21.2R3-S2; 21.3 versions prior to 21.3R3-S1; 21.4 versions prior to 21.4R2-S1, 21.4R3; 22.1 versions prior to 22.1R2; 22.2 versions prior to 22.2R2.

Affected products

Juniper Junos OS: before 19.3; 19.3, 19.3-r1, 19.3-r1-s1, 19.3-r2, 19.3-r2-s1, 19.3-r2-s2 (+111) — fixed in 19.3

How to fix

Upgrade to a fixed version: Juniper Junos OS 19.3. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2023-28979 or the next vulnerability affects your stack