CVE-2024-21585

published 2024-01-12

CVE-2024-21585: An Improper Handling of Exceptional Conditions vulnerability in BGP session processing of Juniper Networks Junos OS and Junos OS Evolved allows an…

Priority P4 31 medium 5.9 CVSS 3.1

AV N AC H PR N UI N S U C N I N A H

An Improper Handling of Exceptional Conditions vulnerability in BGP session processing of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated network-based attacker, using specific timing outside the attacker's control, to flap BGP sessions and cause the routing protocol daemon (rpd) process to crash and restart, leading to a Denial of Service (DoS) condition. Continued BGP session flapping will create a sustained Denial of Service (DoS) condition.

This issue only affects routers configured with non-stop routing (NSR) enabled. Graceful Restart (GR) helper mode, enabled by default, is also required for this issue to be exploitable.

Note: NSR is not supported on the SRX Series and is therefore not affected by this vulnerability.
When the BGP session flaps on the NSR-enabled router, the device enters GR-helper/LLGR-helper mode due to the peer having negotiated GR/LLGR-restarter capability and the backup BGP requests for replication of the GR/LLGR-helper session, master BGP schedules, and initiates replication of GR/LLGR stale routes to the backup BGP. In this state, if the BGP session with the BGP peer comes up again, unsolicited replication is initiated for the peer without cleaning up the ongoing GR/LLGR-helper mode replication. This parallel two instances of replication for the same peer leads to the assert if the BGP session flaps again.

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-S5;
* 22.1 versions earlier than 22.1R3-S4;
* 22.2 versions earlier than 22.2R3-S3;
* 22.3 versions earlier than 22.3R3-S1;
* 22.4 versions earlier than 22.4R2-S2, 22.4R3;
* 23.2 versions earlier than 23.2R1-S1, 23.2R2.

Juniper Networks Junos OS Evolved

* All versions earlier than 21.3R3-S5-EVO;
* 21.4 versions earlier than 21.4R3-S5-EVO;
* 22.1 versions earlier than 22.1R3-S4-EVO;
* 22.2 versions earli

Affected

34 ranges · showing 25

Vendor	Product	Version range	Fixed in
juniper	junos	—	—
juniper	junos	—	—
juniper	junos	—	—
juniper	junos	—	—
juniper	junos	—	—
juniper	junos	—	—
juniper	junos	—	—
juniper	junos	—	—
juniper	junos	—	—
juniper	junos_os	—	—
juniper	junos_os_evolved	—	—
juniper	junos_os_evolved	—	—
juniper	junos_os_evolved	—	—
juniper	junos_os_evolved	—	—
juniper	junos_os_evolved	—	—
juniper	junos_os_evolved	—	—
juniper	junos_os_evolved	—	—
juniper	srx_series	—	—
juniper_networks	junos_os	< 20.4R3-S9	20.4R3-S9
juniper_networks	junos_os	>= 21.2 < 21.2R3-S7	21.2R3-S7
juniper_networks	junos_os	>= 21.3 < 21.3R3-S5	21.3R3-S5
juniper_networks	junos_os	>= 21.4 < 21.4R3-S5	21.4R3-S5
juniper_networks	junos_os	>= 22.1 < 22.1R3-S4	22.1R3-S4
juniper_networks	junos_os	>= 22.2 < 22.2R3-S3	22.2R3-S3
juniper_networks	junos_os	>= 22.3 < 22.3R3-S1	22.3R3-S1

Stop checking back — get the weekly exploitation signal.

Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.

CWE-755