Juniper Networks Junos OS Evolved prior 23.4R2-EVO on ACX7000 PFE Management Daemon buffer overflow

Summaryinfo

A vulnerability identified as critical has been detected in Juniper Networks Junos OS Evolved on ACX7000. This vulnerability affects unknown code of the component PFE Management Daemon. The manipulation leads to buffer overflow. This vulnerability is referenced as CVE-2024-39538. The attack needs to be initiated within the local network. No exploit is available. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in Juniper Networks Junos OS Evolved on ACX7000 and classified as critical. This issue affects some unknown functionality of the component PFE Management Daemon. The manipulation with an unknown input leads to a buffer overflow vulnerability. Using CWE to declare the problem leads to CWE-120. The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer, leading to a buffer overflow. Impacted is availability. The summary by CVE is:

A Buffer Copy without Checking Size of Input vulnerability in the PFE management daemon (evo-pfemand) of Juniper Networks Junos OS Evolved on ACX7000 Series allows an unauthenticated, adjacent attacker to cause a  Denial-of-Service (DoS).When multicast traffic with a specific, valid (S,G) is received, evo-pfemand crashes which leads to an outage of the affected FPC until it is manually recovered. This issue affects Junos OS Evolved on ACX7000 Series: * All versions before 21.2R3-S8-EVO, * 21.4-EVO versions before 21.4R3-S7-EVO, * 22.2-EVO versions before 22.2R3-S4-EVO, * 22.3-EVO versions before 22.3R3-S3-EVO,  * 22.4-EVO versions before 22.4R3-S2-EVO,  * 23.2-EVO versions before 23.2R2-EVO,  * 23.4-EVO versions before 23.4R1-S2-EVO, 23.4R2-EVO.

It is possible to read the advisory at supportportal.juniper.net. The identification of this vulnerability is CVE-2024-39538 since 06/25/2024. The exploitation is known to be easy. The attack can only be initiated within the local network. No form of authentication is needed for a successful exploitation. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 01/23/2026).

Upgrading to version 21.2R3-S8-EVO, 21.4R3-S7-EVO, 22.2R3-S4-EVO, 22.3R3-S3-EVO, 22.4R3-S2-EVO, 23.2R2-EVO, 23.4R1-S2-EVO or 23.4R2-EVO eliminates this vulnerability.

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Productinfo

Type

• Router Operating System

Vendor

• Juniper Networks

Name

• Junos OS Evolved

License

• commercial

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