CVE-2023-28984

/// Technical description

A Use After Free vulnerability in the Layer 2 Address Learning Manager (l2alm) of Juniper Networks Junos OS on QFX Series allows an adjacent attacker to cause the Packet Forwarding Engine to crash and restart, leading to a Denial of Service (DoS). The PFE may crash when a lot of MAC learning and aging happens, but due to a Race Condition (Concurrent Execution using Shared Resource with Improper Synchronization) that is outside the attackers direct control. This issue affects: Juniper Networks Junos OS versions prior to 19.4R3-S10 on QFX Series; 20.2 versions prior to 20.2R3-S7 on QFX Series; 20.3 versions prior to 20.3R3-S6 on QFX Series; 20.4 versions prior to 20.4R3-S5 on QFX Series; 21.1 versions prior to 21.1R3-S4 on QFX Series; 21.2 versions prior to 21.2R3-S3 on QFX Series; 21.3 versions prior to 21.3R3-S3 on QFX Series; 21.4 versions prior to 21.4R3 on QFX Series; 22.1 versions prior to 22.1R3 on QFX Series; 22.2 versions prior to 22.2R2 on QFX Series.

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References