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Uncontrolled Resource ConsumptionWeakness · CWE-400

CVE-2023-20125

HIGH · 8.6 CVSS v3.1 Published 2024-11-15
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
95/100
Remediation priority · Urgent
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 vulnerability in the local interface of Cisco BroadWorks Network Server could allow an unauthenticated, remote attacker to exhaust system resources, causing a denial of service (DoS) condition. This vulnerability exists because rate limiting does not occur for certain incoming TCP connections. An attacker could exploit this vulnerability by sending a high rate of TCP connections to the server. A successful exploit could allow the attacker to cause TCP connection resources to grow rapidly until the Cisco BroadWorks Network Server becomes unusable. Note: To recover from this vulnerability, either Cisco BroadWorks Network Server software must be restarted or the Cisco BroadWorks Network Server node must be rebooted. For more information, see the section of this advisory. Cisco has released software updates that address this vulnerability. There are no workarounds that address 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 · moderate confidence

This is a denial-of-service vulnerability in Cisco BroadWorks Network Server's local interface where lack of rate limiting on certain incoming TCP connections allows an unauthenticated remote attacker to rapidly exhaust TCP connection resources. Successful exploitation renders the server unusable until restart or reboot.

MitigationApply the Cisco software update to address the missing rate limiting. Since no workarounds exist, patching is the only remediation path.

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

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
Changed
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/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. Confirm Cisco BroadWorks Network Server is installed
    Identify the running product by checking system inventory, installed packages, or running processes for 'BroadWorks' or 'bw' related services. On the server, run: ps aux | grep -i broadworks or check installed software packages.
    Affected if The system is running Cisco BroadWorks Network Server software.
  2. Verify TCP connection handling configuration
    Review the BroadWorks configuration files and CLI settings for any rate limiting, connection throttling, or connection pool limits applied to incoming TCP connections. Check configuration directories typically under /opt/broadworks or as specified in your deployment.
    Affected if No rate limiting or connection throttling is configured for incoming TCP connections.
  3. Monitor current TCP connection state
    Run netstat -an | grep -c ESTABLISHED or ss -tan state established to observe the current number of active TCP connections. Compare against expected baseline for your deployment.
    Affected if Connection counts rapidly increase beyond normal operational levels without rate limiting enforcement.
  4. Check for connection resource exhaustion symptoms
    Review system logs (/var/log/messages, /var/log/syslog) and BroadWorks application logs for warnings about connection limits, file descriptor exhaustion, or memory pressure related to TCP connections.
    Affected if Logs show connection resource warnings or the server becomes unresponsive due to connection table exhaustion.
  5. Compare installed BroadWorks version to patch status
    Query the installed BroadWorks version via CLI (typically 'show version' or 'admin> show system info') and compare against the Cisco advisory to determine if the security update has been applied.
    Affected if The installed version is older than the patched release that addresses CVE-2023-20125.

A defender is affected if they run Cisco BroadWorks Network Server without the security update applied and without external rate limiting controls on incoming TCP connections.

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.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply the Cisco software update to address the missing rate limiting. Since no workarounds exist, patching is the only remediation path.

Have this fixed Scoped from the published advisory
  • Consultation6.0 h
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA4.0 h
22.0 hours of engineering $3,960
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Scan for this in your stack

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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-2023-20125 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data