CVE-2024-39511

/// Technical description

An Improper Input Validation vulnerability in the 802.1X Authentication (dot1x) Daemon of Juniper Networks Junos OS allows a local, low-privileged attacker with access to the CLI to cause a Denial of Service (DoS).

On running a specific operational dot1x command, the dot1x daemon crashes. An attacker can cause a sustained DoS condition by running this command repeatedly.

When the crash occurs, the authentication status of any 802.1x clients is cleared, and any authorized dot1x port becomes unauthorized. The client cannot re-authenticate until the dot1x daemon restarts.

This issue affects Junos OS:

* All versions before 20.4R3-S10;

* 21.2 versions before 21.2R3-S7;

* 21.4 versions before 21.4R3-S6;

* 22.1 versions before 22.1R3-S5;

* 22.2 versions before 22.2R3-S3;

* 22.3 versions before 22.3R3-S2;

* 22.4 versions before 22.4R3-S1;

* 23.2 versions before 23.2R2.

/// 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