Juniper Junos OS up to 24.2R1 on MX Packet Forwarding Engine memory leak

Summaryinfo

A vulnerability identified as problematic has been detected in Juniper Junos OS up to 24.2R1 on MX. This vulnerability affects unknown code of the component Packet Forwarding Engine. This manipulation causes memory leak. This vulnerability is registered as CVE-2025-30647. The attack requires access to the local network. No exploit is available. You should upgrade the affected component.

Detailsinfo

A vulnerability has been found in Juniper Junos OS up to 24.2R1 on MX and classified as critical. Affected by this vulnerability is some unknown functionality of the component Packet Forwarding Engine. The manipulation with an unknown input leads to a memory leak vulnerability. The CWE definition for the vulnerability is CWE-401. The product does not sufficiently track and release allocated memory after it has been used, which slowly consumes remaining memory. As an impact it is known to affect availability. The summary by CVE is:

A Missing Release of Memory after Effective Lifetime vulnerability in the packet forwarding engine (PFE) of Juniper Networks Junos OS on MX Series allows an unauthenticated adjacent attacker to cause a Denial-of-Service (DoS). In a subscriber management scenario, login/logout activity triggers a memory leak, and the leaked memory gradually increments and eventually results in a crash.                 user@host> show chassis fpc                                        Temp    CPU Utilization (%)   CPU Utilization (%)   Memory     Utilization (%)                       Slot State       (C)     Total   Interrupt     1min   5min  15min    DRAM (MB)  Heap   Buffer                       2 Online         36       10         0          9     8     9        32768      26         0                                                                                                       This issue affects Junos OS on MX Series: * All versions before 21.2R3-S9 * from 21.4 before 21.4R3-S10 * from 22.2 before 22.2R3-S6 * from 22.4 before 22.4R3-S5 * from 23.2 before 23.2R2-S3 * from 23.4 before 23.4R2-S3 * from 24.2 before 24.2R2.

The advisory is shared at supportportal.juniper.net. This vulnerability is known as CVE-2025-30647 since 03/24/2025. The exploitation appears to be easy. The attack can only be initiated within the local network. The exploitation doesn't need any form of authentication. Neither technical details nor an exploit are publicly available.

The vulnerability scanner Nessus provides a plugin with the ID 234101 (Juniper Junos OS Vulnerability (JSA96457)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 21.2R3-S9, 21.4R3-S10, 22.2R3-S6, 22.4R3-S5, 23.2R2-S3, 23.4R2-S3 or 24.2R2 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (234101). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Type

• Router Operating System

Vendor

• Juniper

Name

• Junos OS

Version

• 21.2R3-S8
• 22.2R3-S5
• 22.4R3-S4
• 23.2R2-S2
• 23.4R2-S2
• 24.2R1

License

• commercial

Website

• Vendor: https://www.juniper.net/

CPE 2.3info

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CPE 2.2info

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Entryinfo

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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