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JunosOperating system · Juniper

CVE-2024-39554

MEDIUM · 5.9 CVSS v3.1 Published 2024-07-10
Fix available
A fix is available. Upgrade to 21.2 / 21.3 or later.
See remediation →
68/100
Remediation priority · Elevated
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 Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') vulnerability the Routing Protocol Daemon (rpd) of Juniper Networks Junos OS and Juniper Networks Junos OS Evolved allows an unauthenticated, network-based attacker to inject incremental routing updates when BGP multipath is enabled, causing rpd to crash and restart, resulting in a Denial of Service (DoS). Since this is a timing issue (race condition), the successful exploitation of this vulnerability is outside the attacker's control.  However, continued receipt and processing of this packet may create a sustained Denial of Service (DoS) condition. On all Junos OS and Junos OS Evolved platforms with BGP multipath enabled, a specific multipath calculation removes the original next hop from the multipath lead routes nexthop-set. When this change happens, multipath relies on certain internal timing to record the update.  Under certain circumstance and with specific timing, this could result in an rpd crash. This issue only affects systems with BGP multipath enabled. This issue affects: Junos OS: * All versions of 21.1 * from 21.2 before 21.2R3-S7, * from 21.4 before 21.4R3-S6, * from 22.1 before 22.1R3-S5, * from 22.2 before 22.2R3-S3, * from 22.3 before 22.3R3-S2, * from 22.4 before 22.4R3, * from 23.2 before 23.2R2. Junos OS Evolved: * All versions of 21.1-EVO, * All versions of 21.2-EVO, * from 21.4-EVO before 21.4R3-S6-EVO, * from 22.1-EVO before 22.1R3-S5-EVO, * from 22.2-EVO before 22.2R3-S3-EVO, * from 22.3-EVO before 22.3R3-S2-EVO, * from 22.4-EVO before 22.4R3-EVO, * from 23.2-EVO before 23.2R2-EVO. Versions of Junos OS before 21.1R1 are unaffected by this vulnerability. Versions of Junos OS Evolved before 21.1R1-EVO are unaffected by this vulnerability.

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

A race condition in the Routing Protocol Daemon (rpd) in Juniper Junos OS/Evolved allows an unauthenticated network attacker to inject incremental BGP routing updates on systems with BGP multipath enabled, triggering a crash and restart of rpd causing denial of service. The vulnerability stems from improper timing during multipath calculation when the original next hop is removed from the nexthop-set.

MitigationApply the appropriate Juniper vendor patch for your version (21.2R3-S7, 21.4R3-S6, 22.1R3-S5, 22.2R3-S3, 22.3R3-S2, 22.4R3, 23.2R2 or later). As a temporary workaround, consider disabling BGP multipath if operationally feasible.

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:>= 21.1, < 21.2= 21.2= 21.4= 22.1= 22.2= 22.3= 22.4= 23.2
Junos Os EvolvedOperating system
Affected:>= 21.1, < 21.3= 21.4= 22.1= 22.2= 22.3= 22.4= 23.2

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
High
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:H/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. Identify the Junos version
    Run 'show version' on the device CLI to obtain the installed Junos OS or Junos OS Evolved version number
    Affected if The version falls within the affected ranges: Junos >= 21.1 to < 21.2, = 21.2, = 21.4, = 22.1, = 22.2, = 22.3, = 22.4, = 23.2 or Junos Evolved >= 21.1 to < 21.3, = 21.4, = 22.1, = 22.2, = 22.3, = 22.4, = 23.2
  2. Confirm BGP is configured
    Run 'show configuration protocols bgp' to verify if BGP is actively configured on the device
    Affected if BGP is configured and operational on the device
  3. Check if BGP multipath is enabled globally
    Run 'show configuration protocols bgp | display set' and look for 'set protocols bgp multipath' at the global BGP level
    Affected if Global BGP multipath is enabled with 'multipath' at the protocols bgp hierarchy level
  4. Check if BGP multipath is enabled per group or neighbor
    Run 'show configuration protocols bgp group <name>' for each BGP group and look for the 'multipath' or 'multipath-calc-upate' statements under the group or neighbor hierarchy
    Affected if BGP multipath is enabled on any peer group or specific neighbor configuration

The device is affected if it runs a vulnerable Junos version AND has BGP multipath enabled either globally or on any BGP peer group/neighbor, allowing an unauthenticated attacker to crash rpd via crafted BGP updates.

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
Upgrade available Upgrade to 21.2 / 21.3 or later
Fixed in 21.221.3
Interim mitigation

Apply the appropriate Juniper vendor patch for your version (21.2R3-S7, 21.4R3-S6, 22.1R3-S5, 22.2R3-S3, 22.3R3-S2, 22.4R3, 23.2R2 or later). As a temporary workaround, consider disabling BGP multipath if operationally feasible.

Recommended fix High confidence

Upgrade to Junos OS 21.2R3-S7/21.4R3-S6/22.1R3-S5/22.2R3-S3/22.3R3-S2/22.4R3/23.2R2 or later; Junos OS Evolved 21.4R3-S6-EVO/22.1R3-S5-EVO/22.2R3-S3-EVO/22.3R3-S2-EVO/22.4R3-EVO/23.2R2-EVO or later

  1. 1. Identify if BGP multipath is enabled on the device using 'show configuration protocols bgp multipath' or 'show configuration protocols bgp group <group-name> multipath'
  2. 2. If BGP multipath is enabled, plan for an upgrade to a fixed version
  3. 3. Schedule a maintenance window for the upgrade
  4. 4. Back up the current configuration using 'request system configuration save'
  5. 5. Upgrade Junos OS or Junos OS Evolved to the fixed release: 21.2R3-S7 or later for 21.2 branch, 21.4R3-S6 or later for 21.4 branch, 22.1R3-S5 or later for 22.1 branch, 22.2R3-S3 or later for 22.2 branch, 22.3R3-S2 or later for 22.3 branch, 22.4R3 or later for 22.4 branch, 23.2R2 or later for 23.2 branch
  6. 6. After upgrade, verify rpd is running with 'show route summary' and confirm BGP is operational with 'show bgp summary'
  7. 7. Monitor for any rpd restarts with 'show system processes routing'
Caveat Review release notes for any migration considerations; test upgrade in lab environment before deploying to production

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

Fix this in Junos Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA2.0 h
18.0 hours of engineering $3,200
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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-2024-39554 in production — separate from our analysis above.

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