Juniper Networks Junos OS Evolved Tunnel Driver memory leak

Summaryinfo

A vulnerability categorized as problematic has been discovered in Juniper Networks Junos OS Evolved. Affected by this issue is some unknown functionality of the component Tunnel Driver. Such manipulation leads to memory leak. This vulnerability is traded as CVE-2025-21599. The attack may be launched remotely. There is no exploit available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability was found in Juniper Networks Junos OS Evolved and classified as critical. Affected by this issue is an unknown functionality of the component Tunnel Driver. The manipulation with an unknown input leads to a memory leak vulnerability. Using CWE to declare the problem leads to CWE-401. The product does not sufficiently track and release allocated memory after it has been used, which slowly consumes remaining memory. Impacted is availability. CVE summarizes:

A Missing Release of Memory after Effective Lifetime vulnerability in the Juniper Tunnel Driver (jtd) of Juniper Networks Junos OS Evolved allows an unauthenticated network-based attacker to cause Denial of Service.  Receipt of specifically malformed IPv6 packets, destined to the device, causes kernel memory to not be freed, resulting in memory exhaustion leading to a system crash and Denial of Service (DoS). Continuous receipt and processing of these packets will continue to exhaust kernel memory, creating a sustained Denial of Service (DoS) condition. This issue only affects systems configured with IPv6. This issue affects Junos OS Evolved:  * from 22.4-EVO before 22.4R3-S5-EVO,  * from 23.2-EVO before 23.2R2-S2-EVO,  * from 23.4-EVO before 23.4R2-S2-EVO,  * from 24.2-EVO before 24.2R1-S2-EVO, 24.2R2-EVO. This issue does not affect Juniper Networks Junos OS Evolved versions prior to 22.4R1-EVO.

The advisory is shared for download at supportportal.juniper.net. This vulnerability is handled as CVE-2025-21599 since 12/26/2024. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. There are neither technical details nor an exploit publicly available. The MITRE ATT&CK project declares the attack technique as T1499.

The vulnerability scanner Nessus provides a plugin with the ID 213558 (Juniper Junos OS Vulnerability (JSA92869)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 22.4R3-S5-EVO, 23.2R2-S2-EVO, 23.4R2-S2-EVO, 24.2R1-S2-EVO or 24.2R2-EVO eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (213558). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Type

• Router Operating System

Vendor

• Juniper Networks

Name

• Junos OS Evolved

License

• commercial

CPE 2.3info

• 🔍
• 🔍
• 🔍

CPE 2.2info

• 🔍
• 🔍
• 🔍

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

VulDB is the best source for vulnerability data and more expert information about this specific topic.

Discussion