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Unified Communications Manager Im And Presence ServiceApplication · Cisco

CVE-2023-20108

HIGH · 7.5 CVSS v3.1 Published 2023-06-28
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 Authentication Service of the Cisco Unified Communications Manager IM & Presence Service (Unified CM IM&P) could allow an unauthenticated, remote attacker to cause a temporary service outage for all Cisco Unified CM IM&P users who are attempting to authenticate to the service, resulting in a denial of service (DoS) condition. This vulnerability is due to improper validation of user-supplied input. An attacker could exploit this vulnerability by sending a crafted login message to the affected device. A successful exploit could allow the attacker to cause an unexpected restart of the authentication service, preventing new users from successfully authenticating. Exploitation of this vulnerability does not impact Cisco Unified CM IM&P users who were authenticated prior to an attack.

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

This is a denial of service vulnerability in the XCP Authentication Service of Cisco Unified Communications Manager IM & Presence Service. The flaw stems from improper validation of user-supplied input within crafted login messages, allowing unauthenticated remote attackers to trigger an unexpected restart of the authentication service by sending specifically malformed authentication requests.

MitigationApply the vendor patch from Cisco when available. As an interim measure, restrict network access to the XCP Authentication Service ports to trusted sources only.

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
Unified Communications Manager Im And Presence ServiceApplication
Affected:= 12.5\(1\)= 14su

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 Cisco Unified Communications Manager IM & Presence Service installation
    Locate the Cisco Unified Communications Manager IM & Presence Service (CUCM IM&P) on the system. This is typically installed as a dedicated server or virtual machine. Check system inventory or running services for 'Cisco Unified Communications Manager IM and Presence Service' or related processes.
    Affected if The product is installed and the version matches 12.5(1) or 14su specifically.
  2. Check installed CUCM IM&P version
    Use the Cisco CLI or admin interface to query the exact version. From the CLI, run 'show version' or access the Disaster Recovery System to verify the version number.
    Affected if The installed version is exactly 12.5(1) or exactly 14su.
  3. Verify XCP Authentication Service is running
    Check if the XCP Authentication Service (xcp_auth) is active. This can be done via the Cisco CLI command 'show process list' or by accessing the service status page in the CUCM Administration interface under Cisco Unified Serviceability > Service Activation.
    Affected if The XCP Authentication Service is running and enabled on the affected version.
  4. Check network exposure of XCP Authentication Service ports
    Identify the ports used by the XCP Authentication Service (typically port 8443 or similar for XCP services). Use 'netstat' or firewall rules to determine if these ports are accessible from untrusted network sources.
    Affected if The XCP Authentication Service ports are exposed to untrusted network sources (internet-facing or untrusted internal networks).

A user is affected if they have Cisco Unified Communications Manager IM & Presence Service version 12.5(1) or 14su running with the XCP Authentication Service exposed to network access.

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 vendor patch from Cisco when available. As an interim measure, restrict network access to the XCP Authentication Service ports to trusted sources only.

Fix this in Unified Communications Manager Im And Presence Service Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing4.0 h
  • Review / QA2.0 h
12.0 hours of engineering $2,080
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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-2023-20108 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