CVE-2024-21609: Junos OS: MX Series with SPC3, and SRX Series: If specific IPsec parameters are negotiated iked will crash due to a memory leak

Severity: medium (CVSS 6.5 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: 2024-04-12 · updated 2026-06-17
Weakness: CWE-401

Description

A Missing Release of Memory after Effective Lifetime vulnerability in the IKE daemon (iked) of Juniper Networks Junos OS on MX Series with SPC3, and SRX Series allows an administratively adjacent attacker which is able to successfully establish IPsec tunnels to cause a Denial of Service (DoS). If specific values for the IPsec parameters local-ip, remote-ip, remote ike-id, and traffic selectors are sent from the peer, a memory leak occurs during every IPsec SA rekey which is carried out with a specific message sequence. This will eventually result in an iked process crash and restart. The iked process memory consumption can be checked using the below command: user@host> show system processes extensive | grep iked PID USERNAME PRI NICE SIZE RES STATE C TIME WCPU COMMAND 56903 root 31 0 4016M 2543M CPU0 0 2:10 10.50% iked This issue affects Juniper Networks Junos OS: * All versions earlier than 20.4R3-S9; * 21.2 versions earlier than 21.2R3-S7; * 21.3 versions earlier than 21.3R3-S5; * 21.4 versions earlier than 21.4R3-S4; * 22.1 versions earlier than 22.1R3-S3; * 22.2 versions earlier than 22.2R3-S2; * 22.3 versions earlier than 22.3R3; * 22.4 versions earlier than 22.4R3; * 23.2 versions earlier than 23.2R1-S2, 23.2R2.

Affected products

Juniper Junos OS: before 20.4; 20.4, 20.4-r1, 20.4-r1-s1, 20.4-r2, 20.4-r2-s1, 20.4-r2-s2 (+82) — fixed in 20.4

How to fix

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

References

Get alerted when CVE-2024-21609 or the next vulnerability affects your stack