Vulnerability Database

346,508

Total vulnerabilities in the database

CVE-2024-39511 — juniper / junos

Improper Input Validation

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.
  • Published: Jul 10, 2024
  • Updated: Nov 16, 2025
  • CVE: CVE-2024-39511
  • Severity: Medium
  • Exploit:

CVSS v3:

  • Severity: Medium
  • Score: 5.5
  • AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CWEs:

Software From Fixed in
juniper / junos 20.4-r1 20.4-r1.x
juniper / junos 20.4-r1-s1 20.4-r1-s1.x
juniper / junos 20.4-r2 20.4-r2.x
juniper / junos 21.2-r1 21.2-r1.x
juniper / junos 20.4-r2-s1 20.4-r2-s1.x
juniper / junos 21.2-r1-s1 21.2-r1-s1.x
juniper / junos 20.4 20.4.x
juniper / junos 20.4-r2-s2 20.4-r2-s2.x
juniper / junos 20.4-r3 20.4-r3.x
juniper / junos 20.4-r3-s1 20.4-r3-s1.x
juniper / junos 21.2 21.2.x
juniper / junos 21.2-r1-s2 21.2-r1-s2.x
juniper / junos 21.2-r2 21.2-r2.x
juniper / junos 21.2-r2-s1 21.2-r2-s1.x
juniper / junos 21.2-r2-s2 21.2-r2-s2.x
juniper / junos 21.4-r1 21.4-r1.x
juniper / junos 21.4-r1-s1 21.4-r1-s1.x
juniper / junos 21.4-r1-s2 21.4-r1-s2.x
juniper / junos 20.4-r3-s2 20.4-r3-s2.x
juniper / junos 20.4-r3-s3 20.4-r3-s3.x
juniper / junos 20.4-r3-s4 20.4-r3-s4.x
juniper / junos 20.4-r3-s5 20.4-r3-s5.x
juniper / junos 21.2-r3 21.2-r3.x
juniper / junos 21.2-r3-s1 21.2-r3-s1.x
juniper / junos 21.2-r3-s2 21.2-r3-s2.x
juniper / junos 21.4 21.4.x
juniper / junos 21.4-r2 21.4-r2.x
juniper / junos 21.4-r2-s1 21.4-r2-s1.x
juniper / junos 21.4-r2-s2 21.4-r2-s2.x
juniper / junos 21.4-r3 21.4-r3.x
juniper / junos 22.1-r1 22.1-r1.x
juniper / junos 22.1-r1-s1 22.1-r1-s1.x
juniper / junos 22.1-r1-s2 22.1-r1-s2.x
juniper / junos 22.1-r2 22.1-r2.x
juniper / junos 22.1-r2-s2 22.1-r2-s2.x
juniper / junos 22.1-r3 22.1-r3.x
juniper / junos 22.1-r3-s1 22.1-r3-s1.x
juniper / junos 22.2-r1 22.2-r1.x
juniper / junos 22.2-r1-s1 22.2-r1-s1.x
juniper / junos 22.2-r2 22.2-r2.x
juniper / junos 22.3-r1 22.3-r1.x
juniper / junos 22.3-r2 22.3-r2.x
juniper / junos - 20.4
juniper / junos 20.4-r3-s6 20.4-r3-s6.x
juniper / junos 20.4-r3-s7 20.4-r3-s7.x
juniper / junos 20.4-r3-s8 20.4-r3-s8.x
juniper / junos 20.4-r3-s9 20.4-r3-s9.x
juniper / junos 21.2-r3-s3 21.2-r3-s3.x
juniper / junos 21.2-r3-s4 21.2-r3-s4.x
juniper / junos 21.2-r3-s5 21.2-r3-s5.x
juniper / junos 21.2-r3-s6 21.2-r3-s6.x
juniper / junos 21.4-r3-s1 21.4-r3-s1.x
juniper / junos 21.4-r3-s2 21.4-r3-s2.x
juniper / junos 21.4-r3-s3 21.4-r3-s3.x
juniper / junos 21.4-r3-s4 21.4-r3-s4.x
juniper / junos 21.4-r3-s5 21.4-r3-s5.x
juniper / junos 22.1 22.1.x
juniper / junos 22.1-r2-s1 22.1-r2-s1.x
juniper / junos 22.1-r3-s2 22.1-r3-s2.x
juniper / junos 22.1-r3-s3 22.1-r3-s3.x
juniper / junos 22.1-r3-s4 22.1-r3-s4.x
juniper / junos 22.2 22.2.x
juniper / junos 22.2-r1-s2 22.2-r1-s2.x
juniper / junos 22.2-r2-s1 22.2-r2-s1.x
juniper / junos 22.2-r2-s2 22.2-r2-s2.x
juniper / junos 22.2-r3 22.2-r3.x
juniper / junos 22.2-r3-s1 22.2-r3-s1.x
juniper / junos 22.2-r3-s2 22.2-r3-s2.x
juniper / junos 22.3 22.3.x
juniper / junos 22.3-r1-s1 22.3-r1-s1.x
juniper / junos 22.3-r1-s2 22.3-r1-s2.x
juniper / junos 22.3-r2-s1 22.3-r2-s1.x
juniper / junos 22.3-r2-s2 22.3-r2-s2.x
juniper / junos 22.3-r3 22.3-r3.x
juniper / junos 22.3-r3-s1 22.3-r3-s1.x
juniper / junos 22.4 22.4.x
juniper / junos 22.4-r1 22.4-r1.x
juniper / junos 22.4-r1-s1 22.4-r1-s1.x
juniper / junos 22.4-r1-s2 22.4-r1-s2.x
juniper / junos 22.4-r2 22.4-r2.x
juniper / junos 22.4-r2-s1 22.4-r2-s1.x
juniper / junos 22.4-r2-s2 22.4-r2-s2.x
juniper / junos 22.4-r3 22.4-r3.x
juniper / junos 23.2 23.2.x
juniper / junos 23.2-r1 23.2-r1.x
juniper / junos 23.2-r1-s1 23.2-r1-s1.x
juniper / junos 23.2-r1-s2 23.2-r1-s2.x

Frequently Asked Questions

A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.

CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.

A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. In practice, risk increases sharply when exploitation becomes reliable or widespread.

Recurring findings usually come from incomplete Asset Discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host. Unknown or unmanaged assets (often called Shadow IT) are a common reason the same issues resurface.

Use a simple, repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress using consistent metrics so remediation is steady, not reactive.

SynScan combines attack surface monitoring and continuous security auditing to keep your inventory current, flag high-impact vulnerabilities early, and help you turn raw findings into a practical remediation plan.