Juniper Networks Junos OS/Junos OS Evolved stack-based overflow

Summaryinfo

A vulnerability classified as critical was found in Juniper Networks Junos OS and Junos OS Evolved. The impacted element is an unknown function. Such manipulation leads to stack-based overflow. This vulnerability is traded as CVE-2024-39556. An attack has to be approached locally. There is no exploit available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in Juniper Networks Junos OS and Junos OS Evolved (version unknown). It has been rated as critical. Affected by this issue is an unknown function. The manipulation with an unknown input leads to a stack-based overflow vulnerability. Using CWE to declare the problem leads to CWE-121. A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function). Impacted is confidentiality, integrity, and availability. CVE summarizes:

A Stack-Based Buffer Overflow vulnerability in Juniper Networks Junos OS and Juniper Networks Junos OS Evolved may allow a local, low-privileged attacker with access to the CLI the ability to load a malicious certificate file, leading to a limited Denial of Service (DoS) or privileged code execution. By exploiting the 'set security certificates' command with a crafted certificate file, a malicious attacker with access to the CLI could cause a crash of the command management daemon (mgd), limited to the local user's command interpreter, or potentially trigger a stack-based buffer overflow. This issue affects:  Junos OS: * All versions before 21.4R3-S7, * from 22.1 before 22.1R3-S6, * from 22.2 before 22.2R3-S4, * from 22.3 before 22.3R3-S3, * from 22.4 before 22.4R3-S2, * from 23.2 before 23.2R2, * from 23.4 before 23.4R1-S1, 23.4R2;  Junos OS Evolved: * All versions before 21.4R3-S7-EVO, * from 22.1-EVO before 22.1R3-S6-EVO, * from 22.2-EVO before 22.2R3-S4-EVO, * from 22.3-EVO before 22.3R3-S3-EVO, * from 22.4-EVO before 22.4R3-S2-EVO, * from 23.2-EVO before 23.2R2-EVO, * from 23.4-EVO before 23.4R1-S1-EVO, 23.4R2-EVO.

The advisory is shared for download at supportportal.juniper.net. This vulnerability is handled as CVE-2024-39556 since 06/25/2024. The exploitation is known to be easy. The attack needs to be approached locally. Additional levels of successful authentication are needed for exploitation. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 04/29/2026).

The vulnerability scanner Nessus provides a plugin with the ID 310746 (Juniper Junos OS Vulnerability (JSA83016)), which helps to determine the existence of the flaw in a target environment.

Upgrading eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (310746). Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

• Router Operating System

Vendor

• Juniper Networks

Name

• Junos OS
• Junos OS Evolved

License

• commercial

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Once again VulDB remains the best source for vulnerability data.

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