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Telepresence Video Communication ServerApplication · Cisco

CVE-2018-0409

HIGH · 7.5 CVSS v3.1 Published 2018-08-15
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 vulnerability in the XCP Router service of the Cisco Unified Communications Manager IM & Presence Service (CUCM IM&P) and the Cisco TelePresence Video Communication Server (VCS) and Expressway could allow an unauthenticated, remote attacker to cause a temporary service outage for all IM&P users, resulting in a denial of service (DoS) condition. The vulnerability is due to improper validation of user-supplied input. An attacker could exploit this vulnerability by sending a malicious IPv4 or IPv6 packet to an affected device on TCP port 7400. An exploit could allow the attacker to overread a buffer, resulting in a crash and restart of the XCP Router service. Cisco Bug IDs: CSCvg97663, CSCvi55947.

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

Buffer overread vulnerability in the XCP Router service of Cisco CUCM IM&P and TelePresence VCS/Expressway allows unauthenticated remote attackers to crash the service by sending malformed IPv4/IPv6 packets to TCP port 7400, causing a denial of service.

MitigationApply Cisco patches CSCvg97663 and CSCvi55947 to affected systems; alternatively, block TCP port 7400 at the network perimeter or disable the XCP Router service if not required.

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
Telepresence Video Communication ServerApplication
Affected:= x7.0.1= x7.2.4= x8.1= x8.2.2= x8.5= x8.6= x8.7= x8.8= x8.9= x8.10= x8.10.4
Unified Communications Manager Im And Presence ServiceApplication
Affected:= 11.5= 11.5\(1\)

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. Identify VCS/Expressway version
    Access the VCS admin interface and navigate to About > System Information, or run 'xCommand SystemUnitInfo' via CLI to retrieve the exact software version
    Affected if The installed version matches any of these: 7.0.1, 7.2.4, 8.1, 8.2.2, 8.5, 8.6, 8.7, 8.8, 8.9, 8.10, or 8.10.4
  2. Identify CUCM IM&P version
    From the Cisco Unified CM Administration interface, go to Help > About, or run 'show version' via CLI on the IM&P node
    Affected if The installed version is 11.5 or 11.5(1)
  3. Confirm XCP Router service is enabled
    On VCS/Expressway: navigate to Applications > XCP Router status page in admin interface, or run 'xCommand XcpRouterStatus' via CLI. On CUCM IM&P: check Cisco Unified Serviceability > Tools > Control Center - Network Services to verify XCP Router service is started
    Affected if The XCP Router service is running or enabled on the system
  4. Verify TCP port 7400 is listening
    Run 'netstat -an | grep 7400' or 'ss -tlnp | grep 7400' on the system CLI to check if port 7400 is in LISTEN state, or scan the system externally using 'nmap -p 7400 <target>'
    Affected if TCP port 7400 is open and accepting connections

The system is affected if it runs a vulnerable VCS/Expressway version (7.0.1 through 8.10.4) or CUCM IM&P version 11.5/11.5(1), has the XCP Router service enabled, and has TCP port 7400 exposed.

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 Cisco patches CSCvg97663 and CSCvi55947 to affected systems; alternatively, block TCP port 7400 at the network perimeter or disable the XCP Router service if not required.

Fix this in Telepresence Video Communication Server Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing3.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,490
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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-2018-0409 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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