CVE-2025-21598
Published: 09 January 2025
Summary
CVE-2025-21598 is a high-severity Out-of-bounds Read (CWE-125) vulnerability in Juniper Junos. Its CVSS base score is 7.5 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Application or System Exploitation (T1499.004); ranked in the top 36.5% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified are NIST 800-53 CM-7 (Least Functionality) and SI-2 (Flaw Remediation).
Threat & Defense at a Glance
Threat & Defense Details
Mitigating Controls (NIST 800-53 r5)AI
Directly mitigates the out-of-bounds read vulnerability by requiring timely remediation through vendor patches to fixed Junos OS versions.
Prevents exploitation by restricting BGP packet receive traceoptions to least functionality, as the vulnerability requires this non-essential configuration to be enabled.
Addresses the DoS impact from malformed BGP packets by implementing protections to identify, block, or limit effects of invalid network traffic.
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Out-of-bounds read in rpd triggered by malformed BGP packets over established session directly enables remote application/system crash (DoS).
NVD 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.…
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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
Deeper analysisAI
CVE-2025-21598 is an out-of-bounds read vulnerability (CWE-125) in the routing protocol daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved. It affects Junos OS versions from 21.2R3-S8 before 21.2R3-S9, 21.4R3-S7 before 21.4R3-S9, 22.2R3-S4 before 22.2R3-S5, 22.3R3-S2 before 22.3R3-S4, 22.4R3 before 22.4R3-S5, 23.2R2 before 23.2R2-S2, 23.4R1 before 23.4R2-S1, and 24.2R1 before 24.2R1-S1 or 24.2R2; and corresponding Junos OS Evolved versions from 21.4R3-S7-EVO before 21.4R3-S9-EVO through 24.2R2-EVO. The vulnerability has a CVSS v3.1 base score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).
An unauthenticated, network-based attacker can exploit this vulnerability by sending malformed BGP packets to a targeted device configured with BGP packet receive trace options enabled, causing the rpd process to crash. Exploitation requires an established BGP session and affects both iBGP and eBGP over IPv4 and IPv6. Malformed packets can propagate and multiply across multiple autonomous systems until they reach vulnerable devices.
The Juniper security advisory at https://supportportal.juniper.net/JSA92867 details the affected versions and recommends upgrading to the listed fixed releases. Documentation on BGP traceoptions configuration is available at https://www.juniper.net/documentation/us/en/software/junos/cli-reference/topics/ref/statement/traceoptions-edit-protocols-bgp.html. Indicators of compromise include log messages on neighboring unaffected devices, such as "rpd[<pid>]: Received malformed update from <IP address> (External AS <AS#>) " and "rpd[<pid>]: Malformed Attribute", which may appear in proximity to multiple devices.
Details
- CWE(s)