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JunosOperating system · Juniper

CVE-2024-21611

HIGH · 7.5 CVSS v3.1 Published 2024-01-12
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
A Missing Release of Memory after Effective Lifetime vulnerability in the Routing Protocol Daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated, network-based attacker to cause a Denial of Service (DoS). In a Juniper Flow Monitoring (jflow) scenario route churn that causes BGP next hops to be updated will cause a slow memory leak and eventually a crash and restart of rpd. Thread level memory utilization for the areas where the leak occurs can be checked using the below command: user@host> show task memory detail | match so_in so_in6 28 32 344450 11022400 344760 11032320 so_in 8 16 1841629 29466064 1841734 29467744 This issue affects: Junos OS * 21.4 versions earlier than 21.4R3; * 22.1 versions earlier than 22.1R3; * 22.2 versions earlier than 22.2R3. Junos OS Evolved * 21.4-EVO versions earlier than 21.4R3-EVO; * 22.1-EVO versions earlier than 22.1R3-EVO; * 22.2-EVO versions earlier than 22.2R3-EVO. This issue does not affect: Juniper Networks Junos OS versions earlier than 21.4R1. Juniper Networks Junos OS Evolved versions earlier than 21.4R1.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Memory leak vulnerability in the Routing Protocol Daemon (rpd) in Juniper Junos OS/Evolved. In Juniper Flow Monitoring (jflow) scenarios, route churn that causes BGP next hop updates leads to a slow memory leak in socket buffer structures (so_in/so_in6), eventually causing rpd to crash and restart. Unauthenticated network-based attackers can trigger this DoS.

MitigationUpgrade Junos OS or Junos OS Evolved to version 21.4R3, 22.1R3, 22.2R3 or later. Monitor thread memory using 'show task memory detail | match so_in' command to detect the leak.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
JunosOperating system
Affected:= 21.4= 22.1= 22.2
Junos Os EvolvedOperating system
Affected:= 21.4= 22.1= 22.2

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check Junos version
    Run 'show version' to obtain the installed Junos OS or Junos OS Evolved version
    Affected if Version equals 21.4, 22.1, or 22.2 (any release within these branches)
  2. Verify jflow is enabled
    Run 'show configuration | display set | match jflow' or 'show services flow-monitoring' to confirm Juniper Flow Monitoring is configured
    Affected if jflow/flow-monitoring is actively enabled on the device
  3. Check for memory leak in socket buffers
    Run 'show task memory detail | match so_in' and look for growing memory usage in so_in or so_in6 structures
    Affected if Memory in so_in or so_in6 structures is continuously increasing or shows abnormal growth
  4. Detect rpd crash history
    Run 'show system core-dumps' or check /var/log/messages for 'rpd' crash entries and restart events
    Affected if rpd has crashed and restarted multiple times, especially under conditions of BGP next hop updates with flow monitoring active

The device is affected if it runs Junos 21.4, 22.1, or 22.2, has jflow enabled, and shows increasing memory in so_in/so_in6 structures or frequent rpd crashes during route churn.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade Junos OS or Junos OS Evolved to version 21.4R3, 22.1R3, 22.2R3 or later. Monitor thread memory using 'show task memory detail | match so_in' command to detect the leak.

Recommended fix High confidence

Junos OS: upgrade to 21.4R3, 22.1R3, or 22.2R3; Junos OS Evolved: upgrade to 21.4R3-EVO, 22.1R3-EVO, or 22.2R3-EVO

  1. Identify current Junos OS or Junos OS Evolved version using 'show version' command
  2. Determine which branch (21.4, 22.1, or 22.2) your current version belongs to
  3. For Junos OS: upgrade to 21.4R3, 22.1R3, or 22.2R3 depending on your current branch
  4. For Junos OS Evolved: upgrade to 21.4R3-EVO, 22.1R3-EVO, or 22.2R3-EVO depending on your current branch
  5. Follow standard Junos upgrade procedures: backup configuration with 'request system snapshot', verify software package integrity, schedule maintenance window
  6. After upgrade, verify rpd is stable using 'show task memory detail | match so_in' to monitor memory utilization
Caveat Standard Junos upgrade risks apply - verify hardware compatibility and review release notes for your specific platform before upgrading

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Junos Scoped from the published advisory
  • Consultation8.0 h
  • Implementation16.0 h
  • Testing8.0 h
  • Review / QA4.0 h
36.0 hours of engineering $6,400
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2024-21611 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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