Junos OS: BGP flap on NSR-enabled devices causes memory leak

Summary

An Incomplete Cleanup vulnerability in Nonstop active routing (NSR) component of Juniper Networks Junos OS allows an adjacent, unauthenticated attacker to cause memory leak leading to Denial of Service (DoS). On all Junos OS platforms, when NSR is enabled, a BGP flap will cause memory leak. A manual reboot of the system will restore the services. Note: NSR is not supported on the SRX Series and is therefore not affected by this vulnerability. The memory usage can be monitored using the below commands. user@host> show chassis routing-engine no-forwarding user@host> show system memory | no-more This issue affects: Juniper Networks Junos OS • 21.2 versions earlier than 21.2R3-S5; • 21.3 versions earlier than 21.3R3-S4; • 21.4 versions earlier than 21.4R3-S4; • 22.1 versions earlier than 22.1R3-S2; • 22.2 versions earlier than 22.2R3-S2; • 22.3 versions earlier than 22.3R2-S1, 22.3R3; • 22.4 versions earlier than 22.4R1-S2, 22.4R2. This issue does not affect Junos OS versions earlier than 20.4R3-S7.

Timeline

1. Jan 12, 2024, 12:57 AM UTCCVE published
2. Jan 12, 2024, 6:12 PM UTCCISA SSVC assessment

   Exploitation: none · Automatable: no · Technical impact: partial

3. Jun 17, 2025, 9:09 PM UTCRecord last updated

Affected versions

• Juniper Networks Junos OS

  From 21.2 · fixed in 21.2R3-S5; From 21.3 · fixed in 21.3R3-S4; From 21.4 · fixed in 21.4R3-S4; From 22.1 · fixed in 22.1R3-S2; From 22.2 · fixed in 22.2R3-S2

References 2