CVE-2025-21598
HighWhat is CVE-2025-21598?
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
CVSS Vector Breakdown
CVSS 3.1Exploitable remotely over the network without requiring access to the local system.
No special conditions required. Exploit can be performed reliably and repeatedly.
No authentication required. Any anonymous user can exploit this vulnerability.
No user interaction required. Exploit runs without any victim action.
Exploiting the vulnerability only affects the vulnerable component itself.
No confidentiality impact. Sensitive data is not exposed.
No integrity impact. Data cannot be modified.
Complete denial of service. The component becomes fully unavailable.
Known Affected Devices
FAQ
CVE-2025-21598 has a CVSS score of 7.5/10, rated as High. This is a high severity vulnerability and should be patched as soon as possible.
CVSS (Common Vulnerability Scoring System) rates vulnerability severity from 0.0 to 10.0. CVE-2025-21598 scores 7.5/10 (High). Scores 9.0–10.0 are Critical, 7.0–8.9 are High, 4.0–6.9 are Medium, and below 4.0 are Low.
The list of devices confirmed to be affected by CVE-2025-21598 is shown in the "Affected Devices" section above. Check your firmware version against the vendor security advisory and apply the latest patch.
Apply the latest firmware or software update from the vendor. Check the References section above for official advisories and patch notes. If no patch is available, consider disabling the affected feature or isolating the device from untrusted networks.