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.