CVE-2024-39516: Junos OS and Junos OS Evolved: With certain BGP options enabled, receipt of specifically malformed BGP update causes RPD crash

Severity: high (CVSS 7.5 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: 2024-10-09 · updated 2026-06-17
Weakness: CWE-125

Description

An Out-of-Bounds Read vulnerability in the routing protocol daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated network-based attacker sending a specifically malformed BGP packet to cause rpd to crash and restart, resulting in a Denial of Service (DoS). Continued receipt and processing of this packet will create a sustained Denial of Service (DoS) condition. This issue only affects systems configured in either of two ways: * systems with BGP traceoptions enabled * systems with BGP traffic engineering configured This issue can affect iBGP and eBGP with any address family configured. The specific attribute involved is non-transitive, and will not propagate across a network. This issue affects: Junos OS: * All versions before 21.4R3-S8, * 22.2 before 22.2R3-S5, * 22.3 before 22.3R3-S4, * 22.4 before 22.4R3-S3, * 23.2 before 23.2R2-S2, * 23.4 before 23.4R2; Junos OS Evolved: * All versions before 21.4R3-S8-EVO, * 22.2-EVO before 22.2R3-S5-EVO, * 22.3-EVO before 22.3R3-S4-EVO, * 22.4-EVO before 22.4R3-S3-EVO, * 23.2-EVO before 23.2R2-S2-EVO, * 23.4-EVO before 23.4R2-EVO.

Affected products

Juniper Junos OS: before 21.4; 21.4, 21.4-r1, 21.4-r1-s1, 21.4-r1-s2, 21.4-r2, 21.4-r2-s1 (+52) — fixed in 21.4
Juniper Networks Junos OS Evolved: before 21.4; 21.4, 21.4-r1, 21.4-r1-s1, 21.4-r1-s2, 21.4-r2, 21.4-r2-s1 (+52) — fixed in 21.4

How to fix

Upgrade to a fixed version: Juniper Junos OS 21.4; Juniper Networks Junos OS Evolved 21.4. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2024-39516 or the next vulnerability affects your stack