CVE-2025-21598 Denial of service in Junos OS
An unauthenticated attacker can crash the routing daemon by sending malformed BGP packets to devices with traceoptions enabled, causing denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2025-21598?
CVE-2025-21598 is a high-severity denial of service vulnerability in Juniper Junos, published on 9 Jan 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
An Out-of-bounds Read vulnerability in Juniper Networks Junos OS and Junos OS Evolved's routing protocol daemon (rpd) allows an unauthenticated, network-based attacker to send malformed BGP packets to a device configured with packet receive trace options enabled to crash rpd. This issue affects:
Junos OS:
* from 21.2R3-S8 before 21.2R3-S9, * from 21.4R3-S7 before 21.4R3-S9, * from 22.2R3-S4 before 22.2R3-S5, * from 22.3R3-S2 before 22.3R3-S4, * from 22.4R3 before 22.4R3-S5, * from 23.2R2 before 23.2R2-S2, * from 23.4R1 before 23.4R2-S1, * from 24.2R1 before 24.2R1-S1, 24.2R2.
Junos OS Evolved: * from 21.4R3-S7-EVO before 21.4R3-S9-EVO, * from 22.2R3-S4-EVO before 22.2R3-S5-EVO, * from 22.3R3-S2-EVO before 22.3R3-S4-EVO, * from 22.4R3-EVO before 22.4R3-S5-EVO, * from 23.2R2-EVO before 23.2R2-S2-EVO, * from 23.4R1-EVO before 23.4R2-S1-EVO, * from 24.2R1-EVO before 24.2R1-S2-EVO, 24.2R2-EVO.
This issue requires a BGP session to be established.
This issue can propagate and multiply through multiple ASes until reaching vulnerable devices.
This issue affects iBGP and eBGP.
This issue affects IPv4 and IPv6.
An indicator of compromise may be the presence of malformed update messages in a neighboring AS which is unaffected by this issue:
For example, by issuing the command on the neighboring device: show log messages
Reviewing for similar messages from devices within proximity to each other may indicate this malformed packet is propagating: rpd[<pid>]: Received malformed update from <IP address> (External AS <AS#>) and rpd[<pid>]: Malformed Attribute
Weakness: CWE-125
Which versions are affected by CVE-2025-21598?
It affects 2 products.
Products include Juniper Junos, Juniper Junos Os Evolved.
How do I fix CVE-2025-21598?
No fix has been published for CVE-2025-21598 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2025-21598 being exploited?
There is no known exploitation of CVE-2025-21598 in the wild and no public exploit code.
Other vulnerabilities in Juniper Junos
- CVE-2023-36845 Juniper Junos OS EX Series and SRX Series PHP External Variable Modification
- CVE-2020-1631 Juniper Junos OS Path Traversal
- CVE-2025-21590 Juniper Junos OS Improper Isolation or Compartmentalization
- CVE-2023-36851 Juniper Junos OS SRX Series Missing Authentication for Critical Function
- CVE-2023-36844 Juniper Junos OS EX Series PHP External Variable Modification
Sources
Also known as GHSA-68jp-4r95-v8vr.