Vulnerability Database

346,508

Total vulnerabilities in the database

CVE-2024-21585 — juniper / junos

Improper Handling of Exceptional Conditions

An Improper Handling of Exceptional Conditions vulnerability in BGP session processing of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated network-based attacker, using specific timing outside the attacker's control, to flap BGP sessions and cause the routing protocol daemon (rpd) process to crash and restart, leading to a Denial of Service (DoS) condition. Continued BGP session flapping will create a sustained Denial of Service (DoS) condition.

This issue only affects routers configured with non-stop routing (NSR) enabled. Graceful Restart (GR) helper mode, enabled by default, is also required for this issue to be exploitable.

Note: NSR is not supported on the SRX Series and is therefore not affected by this vulnerability. When the BGP session flaps on the NSR-enabled router, the device enters GR-helper/LLGR-helper mode due to the peer having negotiated GR/LLGR-restarter capability and the backup BGP requests for replication of the GR/LLGR-helper session, master BGP schedules, and initiates replication of GR/LLGR stale routes to the backup BGP. In this state, if the BGP session with the BGP peer comes up again, unsolicited replication is initiated for the peer without cleaning up the ongoing GR/LLGR-helper mode replication. This parallel two instances of replication for the same peer leads to the assert if the BGP session flaps again.

This issue affects:

Juniper Networks Junos OS

  • All versions earlier than 20.4R3-S9;
  • 21.2 versions earlier than 21.2R3-S7;
  • 21.3 versions earlier than 21.3R3-S5;
  • 21.4 versions earlier than 21.4R3-S5;
  • 22.1 versions earlier than 22.1R3-S4;
  • 22.2 versions earlier than 22.2R3-S3;
  • 22.3 versions earlier than 22.3R3-S1;
  • 22.4 versions earlier than 22.4R2-S2, 22.4R3;
  • 23.2 versions earlier than 23.2R1-S1, 23.2R2.

Juniper Networks Junos OS Evolved

  • All versions earlier than 21.3R3-S5-EVO;
  • 21.4 versions earlier than 21.4R3-S5-EVO;
  • 22.1 versions earlier than 22.1R3-S4-EVO;
  • 22.2 versions earlier than 22.2R3-S3-EVO;
  • 22.3 versions earlier than 22.3R3-S1-EVO;
  • 22.4 versions earlier than 22.4R2-S2-EVO, 22.4R3-EVO;
  • 23.2 versions earlier than 23.2R1-S1-EVO, 23.2R2-EVO.
  • Published: Jan 12, 2024
  • Updated: Nov 16, 2025
  • CVE: CVE-2024-21585
  • Severity: Medium
  • Exploit:

CVSS v3:

  • Severity: Medium
  • Score: 5.9
  • AV:N/AC:H/PR:N/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 20.4-r2-s1 20.4-r2-s1.x
juniper / junos 20.4-r3 20.4-r3.x
juniper / junos 20.4-r3-s1 20.4-r3-s1.x
juniper / junos 20.4-r2-s2 20.4-r2-s2.x
juniper / junos 20.4 20.4.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 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 21.2-r1 21.2-r1.x
juniper / junos 21.2-r1-s1 21.2-r1-s1.x
juniper / junos 21.2-r2 21.2-r2.x
juniper / junos 21.2 21.2.x
juniper / junos 21.2-r1-s2 21.2-r1-s2.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 21.2-r3 21.2-r3.x
juniper / junos 21.2-r3-s2 21.2-r3-s2.x
juniper / junos 21.2-r3-s1 21.2-r3-s1.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 21.3-r1 21.3-r1.x
juniper / junos 21.3-r2 21.3-r2.x
juniper / junos 21.3-r1-s1 21.3-r1-s1.x
juniper / junos 21.3-r1-s2 21.3-r1-s2.x
juniper / junos 21.3-r2-s1 21.3-r2-s1.x
juniper / junos 21.3-r2-s2 21.3-r2-s2.x
juniper / junos 21.3-r3 21.3-r3.x
juniper / junos 21.3-r3-s1 21.3-r3-s1.x
juniper / junos 21.3 21.3.x
juniper / junos 21.3-r3-s2 21.3-r3-s2.x
juniper / junos 21.3-r3-s3 21.3-r3-s3.x
juniper / junos 21.3-r3-s4 21.3-r3-s4.x
juniper / junos 21.4-r1-s1 21.4-r1-s1.x
juniper / junos 21.4-r1 21.4-r1.x
juniper / junos 21.4-r1-s2 21.4-r1-s2.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 21.4.x
juniper / junos 21.4-r3 21.4-r3.x
juniper / junos 21.4-r2-s2 21.4-r2-s2.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 22.1-r1 22.1-r1.x
juniper / junos 22.1-r1-s1 22.1-r1-s1.x
juniper / junos 22.1-r2 22.1-r2.x
juniper / junos 22.1-r1-s2 22.1-r1-s2.x
juniper / junos 22.1-r2-s2 22.1-r2-s2.x
juniper / junos 22.1-r3-s1 22.1-r3-s1.x
juniper / junos 22.1-r3 22.1-r3.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 22.1.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 22.2-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 22.2 22.2.x
juniper / junos 22.3-r1 22.3-r1.x
juniper / junos 22.3-r2 22.3-r2.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-r3 22.3-r3.x
juniper / junos 22.3-r2-s2 22.3-r2-s2.x
juniper / junos 22.3 22.3.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 22.4.x
juniper / junos 23.2-r1 23.2-r1.x
juniper / junos_os_evolved 21.3-r1 21.3-r1.x
juniper / junos_os_evolved 21.3-r1-s1 21.3-r1-s1.x
juniper / junos_os_evolved 21.3-r2 21.3-r2.x
juniper / junos_os_evolved 21.3 21.3.x
juniper / junos_os_evolved 21.3-r2-s1 21.3-r2-s1.x
juniper / junos_os_evolved 21.3-r2-s2 21.3-r2-s2.x
juniper / junos_os_evolved 21.3-r3 21.3-r3.x
juniper / junos_os_evolved 21.3-r3-s1 21.3-r3-s1.x
juniper / junos_os_evolved 21.3-r3-s2 21.3-r3-s2.x
juniper / junos_os_evolved 21.3-r3-s3 21.3-r3-s3.x
juniper / junos_os_evolved 21.3-r3-s4 21.3-r3-s4.x
juniper / junos_os_evolved 21.4-r1 21.4-r1.x
juniper / junos_os_evolved 21.4-r1-s1 21.4-r1-s1.x
juniper / junos_os_evolved 21.4 21.4.x
juniper / junos_os_evolved 21.4-r2 21.4-r2.x
juniper / junos_os_evolved 21.4-r2-s1 21.4-r2-s1.x
juniper / junos_os_evolved 21.4-r2-s2 21.4-r2-s2.x
juniper / junos_os_evolved 21.4-r1-s2 21.4-r1-s2.x
juniper / junos_os_evolved 21.4-r3 21.4-r3.x
juniper / junos_os_evolved 21.4-r3-s1 21.4-r3-s1.x
juniper / junos_os_evolved 21.4-r3-s2 21.4-r3-s2.x
juniper / junos_os_evolved 21.4-r3-s3 21.4-r3-s3.x
juniper / junos_os_evolved 21.4-r3-s4 21.4-r3-s4.x
juniper / junos_os_evolved 22.1-r1 22.1-r1.x
juniper / junos_os_evolved 22.1-r1-s1 22.1-r1-s1.x
juniper / junos_os_evolved 22.1-r1-s2 22.1-r1-s2.x
juniper / junos_os_evolved 22.1-r2 22.1-r2.x
juniper / junos_os_evolved 22.1-r2-s1 22.1-r2-s1.x
juniper / junos_os_evolved 22.1-r3 22.1-r3.x
juniper / junos_os_evolved 22.1-r3-s1 22.1-r3-s1.x
juniper / junos_os_evolved 22.1-r3-s2 22.1-r3-s2.x
juniper / junos_os_evolved 22.1-r3-s3 22.1-r3-s3.x
juniper / junos_os_evolved 22.1 22.1.x
juniper / junos_os_evolved 22.2-r1-s1 22.2-r1-s1.x
juniper / junos_os_evolved 22.2-r1 22.2-r1.x
juniper / junos_os_evolved 22.2-r2 22.2-r2.x
juniper / junos_os_evolved 22.2-r2-s1 22.2-r2-s1.x
juniper / junos_os_evolved 22.2-r2-s2 22.2-r2-s2.x
juniper / junos_os_evolved 22.2-r3 22.2-r3.x
juniper / junos_os_evolved 22.2-r3-s1 22.2-r3-s1.x
juniper / junos_os_evolved 22.2-r3-s2 22.2-r3-s2.x
juniper / junos_os_evolved 22.2 22.2.x
juniper / junos_os_evolved 22.3-r1 22.3-r1.x
juniper / junos_os_evolved 22.3-r1-s1 22.3-r1-s1.x
juniper / junos_os_evolved 22.3-r1-s2 22.3-r1-s2.x
juniper / junos_os_evolved 22.3-r2 22.3-r2.x
juniper / junos_os_evolved 22.3-r2-s1 22.3-r2-s1.x
juniper / junos_os_evolved 22.3-r2-s2 22.3-r2-s2.x
juniper / junos_os_evolved 22.3-r3 22.3-r3.x
juniper / junos_os_evolved 22.3 22.3.x
juniper / junos_os_evolved 22.4-r1 22.4-r1.x
juniper / junos_os_evolved 22.4-r1-s1 22.4-r1-s1.x
juniper / junos_os_evolved 22.4-r1-s2 22.4-r1-s2.x
juniper / junos_os_evolved 22.4-r2 22.4-r2.x
juniper / junos_os_evolved 22.4-r2-s1 22.4-r2-s1.x
juniper / junos_os_evolved 22.4 22.4.x
juniper / junos_os_evolved 23.2 23.2.x
juniper / junos_os_evolved 23.2-r1 23.2-r1.x
juniper / junos_os_evolved 23.2-r2-s1 23.2-r2-s1.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.