CVE-2024-39557

/// Technical description

An Uncontrolled Resource Consumption vulnerability in the

Layer 2 Address Learning Daemon (l2ald)

of Juniper Networks Junos OS Evolved allows an unauthenticated, adjacent attacker to cause a memory leak, eventually exhausting all system memory, leading to a system crash and Denial of Service (DoS).

Certain MAC table updates cause a small amount of memory to leak.  Once memory utilization reaches its limit, the issue will result in a system crash and restart.

To identify the issue, execute the CLI command:

user@device> show platform application-info allocations app l2ald-agent

EVL Object Allocation Statistics:

Node   Application     Context Name                               Live   Allocs   Fails     Guids

re0   l2ald-agent               net::juniper::rtnh::L2Rtinfo       1069096 1069302   0         1069302

re0   l2ald-agent               net::juniper::rtnh::NHOpaqueTlv     114     195       0         195

This issue affects Junos OS Evolv

/// 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