SB2025071824 - Out-of-bounds write in Juniper Junos OS

Security Bulletin ID SB2025071824

CSH Severity

Medium

Patch available

YES

Number of vulnerabilities 1

Exploitation vector Adjecent network

Highest impact Denial of service

Breakdown by Severity

Low
Medium
High
Critical

Description

This security bulletin contains information about 1 vulnerability.

1) Out-of-bounds write (CVE-ID: CVE-2025-52952)

CWE-ID: CWE-787 - Out-of-bounds write

CVSSv4: 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

The vulnerability allows a remote non-authenticated attacker to perform a denial of service (DoS) attack.

An Out-of-bounds Write vulnerability in the connectivity fault management (CFM) daemon of Juniper Networks Junos OS on MX Series with MPC-BUILTIN, MPC1 through MPC9 line cards allows an unauthenticated adjacent attacker to send a malformed packet to the device, leading to an FPC crash and restart, resulting in a Denial of Service (DoS).

Continued receipt and processing of this packet will create a sustained Denial of Service (DoS) condition.

Remediation

Install update from vendor's website.

References

https://supportportal.juniper.net/s/article/2025-07-Security-Bulletin-Junos-OS-MX-Series-with-MPC-BUILTIN-MPC-1-through-MPC-9-Receipt-and-processing-of-a-malformed-packet-causes-one-or-more-FPCs-to-crash-CVE-2025-52952