CVE-2022-22196: Junos OS and Junos OS Evolved: The rpd CPU spikes to 100% after a malformed ISIS TLV has been received

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2022-04-14 · updated 2026-06-17
Weakness: CWE-754

Description

An Improper Check for Unusual or Exceptional Conditions vulnerability in the Routing Protocol Daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved allows an adjacent, unauthenticated attacker with an established ISIS adjacency to cause a Denial of Service (DoS). The rpd CPU spikes to 100% after a malformed ISIS TLV has been received which will lead to processing issues of routing updates and in turn traffic impact. This issue affects: Juniper Networks Junos OS 19.3 versions prior to 19.3R3-S4; 19.4 versions prior to 19.4R2-S6, 19.4R3-S6; 20.1 versions prior to 20.1R3-S2; 20.2 versions prior to 20.2R3-S3; 20.3 versions prior to 20.3R3-S1; 20.4 versions prior to 20.4R3; 21.1 versions prior to 21.1R3; 21.2 versions prior to 21.2R2. Juniper Networks Junos OS Evolved All versions prior to 20.4R3-S3-EVO; 21.2 versions prior to 21.2R2-EVO. This issue does not affect Juniper Networks Junos OS versions prior to 19.3R1.

Affected products

Juniper Junos OS: 19.3-r1, 19.3-r1-s1, 19.3-r2, 19.3-r2-s1, 19.3-r2-s2, 19.3-r2-s3 (+63)
Juniper Networks Junos OS Evolved: before 20.4; 20.4-r1, 20.4-r1-s1, 20.4-r1-s2, 20.4-r2, 20.4-r2-s1, 20.4-r2-s2 (+6) — fixed in 20.4

How to fix

Upgrade to a fixed version: Juniper Networks Junos OS Evolved 20.4. Check the vendor advisory for mitigations.

References

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