Junos OS (SRX firewalls)
CVE-2024-39511: The 802.1X Authentication Daemon crashes on running a specific command
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).
Published
Automatic summary from the vendor's CVE record. We haven't written a full analysis of this vulnerability yet.
Affected and fixed versions
| Product / branch | Fixed in |
|---|---|
| Junos OS 0 | 20.4R3-S10 or later |
| Junos OS 21.2 | 21.2R3-S7 or later |
| Junos OS 21.4 | 21.4R3-S6 or later |
| Junos OS 22.1 | 22.1R3-S5 or later |
| Junos OS 22.2 | 22.2R3-S3 or later |
| Junos OS 22.3 | 22.3R3-S2 or later |
| Junos OS 22.4 | 22.4R3-S1 or later |
| Junos OS 23.2 | 23.2R2 or later |
Always confirm against the vendor advisory, which lists every fixed hotfix.
What it is
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.
Workarounds
There are no known workarounds for this issue.
Exploitation
Juniper SIRT is not aware of any malicious exploitation of this vulnerability.
Sources
KEV status, EPSS score and vendor data refreshed automatically, last on 13 Oct 2026.