#VU108102 Improper check for unusual or exceptional conditions in Junos OS Evolved and Juniper Junos OS - CVE-2025-21597
Vulnerability identifier: #VU108102
Vulnerability risk: Medium
CVSSv4.0: 4.9 [CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]
CVE-ID:
CWE-ID:
CWE-754
Exploitation vector: Local network
Exploit availability: No
Vulnerable software:
Junos OS Evolved
Operating systems & Components /
Operating system
Juniper Junos OS
Operating systems & Components /
Operating system
Vendor: Juniper Networks, Inc.
Description
The vulnerability allows a remote non-authenticated attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to improper check for unusual or exceptional conditions error in routing protocol daemon (rpd). A remote non-authenticated attacker can cause Denial of Service (DoS).
On all Junos OS and Junos OS Evolved platforms, when BGP rib-sharding and update-threading are configured, and a BGP peer flap is done with specific timing, rpd crashes and restarts.
Continuous peer flapping at specific time intervals will result in a sustained Denial of Service (DoS) condition.
Mitigation
Install updates from vendor's website.
Vulnerable software versions
Junos OS Evolved: before 21.2R3-S6-EVO, 21.3R3-S5-EVO, 21.4R3-S4-EVO, 22.1R3-S3-EVO, 22.2R3-S1-EVO, 22.3R3-EVO, 22.4R3-EVO, 23.2R1-EVO, 21.2R3-S6-EVO, 21.2R3-S6-EVO, 21.2R3-S6-EVO, 21.2R3-S6-EVO, 21.2R3-S6-EVO, 21.2R3-S6-EVO, 21.2R3-S6-EVO, 21.2R3-S6-EVO
Juniper Junos OS: before 20.4R3-S8, 21.2R3-S6, 21.3R3-S5, 21.4R3-S4, 22.1R3-S3, 22.2R3-S1, 22.3R3, 22.4R3, 23.2R1, 20.4R3-S8, 20.4R3-S8, 20.4R3-S8, 20.4R3-S8, 20.4R3-S8, 20.4R3-S8, 20.4R3-S8, 20.4R3-S8, 20.4R3-S8
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the local network (LAN).
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
