CVE intelligence and bounded remediation

CVE-2024-21585 — Juniper Junos security vulnerability

Medium CVSS 5.9

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…

Severity
Medium
CVSS
5.9 (3.1)
Published
2024-01-12
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-755

Affected products

  • juniper / junos / 20.4

Showing 1 representative product identities from 148 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Resource exhaustion and denial of service

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Identify attacker-influenced work factors including input size, nesting, compression, fan-out, regex cost, allocation, recursion, retries, and connection lifetime.
  • Map per-request and shared CPU, memory, disk, descriptor, thread, queue, and downstream-service limits.
  • Determine whether authentication, tenancy, quotas, and rate controls apply before expensive processing begins.

Remediate safely

  • Bound input size, nesting, expansion, work, concurrency, queue depth, retries, and execution time before resource-intensive processing.
  • Release resources on every success, error, cancellation, and timeout path and use backpressure instead of unbounded buffering.
  • Update affected components and add small deterministic tests that assert resource ceilings rather than exhausting a host.

Authoritative sources

Complete CVE record and remediation plan

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