CVE-2024-21609: 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

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

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

Description from the National Vulnerability Database, published by sirt@juniper.net

What it means for a small business

Junos OS is network equipment or remote-access software: the box between your office and the internet. These are a favorite target because breaking one opens the whole office.

If an IT provider set it up, ask them to confirm the firmware version and the date it was updated. If nobody looks after it, that's the bigger problem.

How likely is an attack? The Exploit Prediction Scoring System, run by FIRST (the global association of security response teams), puts the odds of this one being exploited in the next 30 days at 0.29%, higher than 22% of CVEs. That’s low, but low isn’t zero, and the odds jump the day someone publishes an exploit. Scored October 29, 2026, updated daily.

Check your own setup

Website check: reads what your site runs from the outside (WordPress version, plugins it can see, old server software) and matches it against this database.
Server check: what your web server says about itself, and whether that version has known flaws.

Sources

Part of the Huttenlocher Technologies vulnerability database, refreshed twice a day from CISA and the NVD. The title, category and plain-language guidance are ours; check the linked record before acting on a detail. This is general guidance, not a review of your systems.

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