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Headend Digital Broadband Delivery SystemOperating system · Cisco

CVE-2015-0743

MEDIUM · 5.0 CVSS v2.0 Published 2015-05-30
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
59/100
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
Cisco Headend System Release allows remote attackers to cause a denial of service (DHCP and TFTP outage) via a flood of crafted UDP traffic, aka Bug ID CSCus04097.

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

The Cisco Headend System Release contains a vulnerability where remote attackers can cause a denial of service affecting DHCP and TFTP services by sending a flood of crafted UDP packets. This disrupts critical infrastructure services that depend on these protocols for IP address allocation and firmware/configuration file transfers.

MitigationImplement network-level controls such as UDP traffic rate limiting, ingress ACLs to filter suspicious UDP traffic, and apply any available Cisco patches for Bug ID CSCus04097. Consider network segmentation to isolate headend systems.

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
Headend Digital Broadband Delivery SystemOperating system
Affected:all versions
Headend System ReleaseOperating system
Affected:= 2.5= 2.7= 3.2= 3.5= 3.7= i4.3

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
Authentication
None
Confidentiality
None
Integrity
None
Availability
Partial

AV:N/AC:L/Au:N/C:N/I:N/A:P

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 Cisco Headend product
    Log into the headend system CLI or check system documentation to determine if it is a Cisco Headend Digital Broadband Delivery System or Cisco Headend System Release device.
    Affected if The system is neither of these product lines (not affected)
  2. Check the installed version number
    Access the system via CLI or management interface and retrieve the software/firmware version using 'show version' or similar command. Compare against these affected versions: 2.5, 2.7, 3.2, 3.5, 3.7, or i4.3.
    Affected if The installed version exactly matches any of these: 2.5, 2.7, 3.2, 3.5, 3.7, or i4.3
  3. Verify DHCP service is exposed to network
    Check if DHCP service (UDP ports 67/68) is enabled and accessible on the headend system by reviewing running services or network listening ports.
    Affected if DHCP service is running and reachable from untrusted network segments
  4. Verify TFTP service is exposed to network
    Check if TFTP service (UDP port 69) is enabled and accessible on the headend system by reviewing running services or network listening ports.
    Affected if TFTP service is running and reachable from untrusted network segments
  5. Check for UDP rate limiting or ACLs
    Review network device configurations (switches/routers) between the headend and untrusted networks for existing UDP traffic rate limiting or access control lists.
    Affected if No UDP rate limiting or ingress ACLs are configured to filter UDP traffic to the headend

A system is affected if it is a Cisco Headend Digital Broadband Delivery System (any version) or Cisco Headend System Release version 2.5, 2.7, 3.2, 3.5, 3.7, or i4.3, AND has DHCP or TFTP services exposed to an untrusted network without UDP traffic filtering in place.

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

Implement network-level controls such as UDP traffic rate limiting, ingress ACLs to filter suspicious UDP traffic, and apply any available Cisco patches for Bug ID CSCus04097. Consider network segmentation to isolate headend systems.

Fix this in Headend Digital Broadband Delivery System Scoped from the published advisory
  • Consultation3.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
12.0 hours of engineering $2,130
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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-2015-0743 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
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  • Version or environment caveats, and links to real fixes
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