This vulnerability (CWE-466) in Juniper Networks Junos OS and Junos OS Evolved arises from a return of pointer value outside the expected range in the fileio library. On EX, QFX, and MX Series devices, a local attacker with low privileges can trigger a Denial-of-Service by issuing a specific 'show l2-learning' command, causing the l2ald process to crash and disrupt layer 2 services temporarily. Affected versions include all versions before 23.2R2-S7, 23.4 versions before 23.4R2-S7, 24.2 versions before 24.2R2, and 24.4 versions before 24.4R1-S2 for Junos OS, and similarly for Junos OS Evolved with slightly different patch versions. The vendor manages remediation for this cloud-hosted service.

A local, low-privileged attacker can cause a Denial-of-Service by crashing the l2ald process on affected Juniper devices, leading to temporary disruption of all layer 2 services until the process automatically restarts. There is no impact on confidentiality or integrity reported.

A patch is available for this vulnerability. The vendor manages remediation for this cloud-hosted service, so users should ensure their devices are updated to the fixed versions: 23.2R2-S7 or later, 23.4R2-S7 or later, 24.2R2 or later, and 24.4R1-S2 or later for Junos OS; and corresponding fixed versions for Junos OS Evolved. Check the vendor advisory for the latest remediation guidance.