Unified Communications ManagerApplication · Cisco
CVE-2022-20789
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 · uneditedA vulnerability in the software upgrade process of Cisco Unified Communications Manager (Unified CM) and Cisco Unified Communications Manager Session Management Edition (Unified CM SME) could allow an authenticated, remote attacker to write arbitrary files on the affected system. This vulnerability is due to improper restrictions applied to a system script. An attacker could exploit this vulnerability by using crafted variables during the execution of a system upgrade. A successful exploit could allow the attacker to overwrite or append arbitrary data to system files using root-level privileges.
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 confidenceA file write vulnerability in Cisco Unified CM and Unified CM SME's software upgrade process allows authenticated remote attackers to write arbitrary files with root privileges by manipulating variables during system upgrade execution. The vulnerability stems from improper restrictions on a system script used during the upgrade procedure.
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 ManagerApplication
= 12.5\(1\)= 14.0CVSS 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
- High
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/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 checksWork through these to decide whether this CVE applies to you.
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Identify Cisco Unified CM installationLocate Cisco Unified Communications Manager or Unified CM SME software on your system. This is typically installed on a dedicated appliance or server. Check for Cisco-specific directories or services.Affected if Cisco Unified CM or Unified CM SME software is present on the system
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Verify installed version against affected rangesDetermine the exact version of Cisco Unified Communications Manager installed. Consult the system via CLI (command: show version) or the administrative interface to retrieve the version number.Affected if The installed version is exactly 12.5(1) or exactly 14.0
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Confirm upgrade functionality is accessibleCheck whether the software upgrade feature is enabled and accessible. Verify if the upgrade UI or CLI commands (such as the system script interface used during upgrades) are available to authenticated users.Affected if Upgrade functionality is present and accessible to authenticated users
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Inspect upgrade-related logs for anomalous behaviorReview system logs related to upgrade operations. Look for unexpected file writes, modification of system scripts, or unusual variable manipulations during recent upgrade attempts.Affected if Logs show unexpected file write operations or script modifications during upgrade execution
You are affected if Cisco Unified CM or Unified CM SME is installed AND the version matches exactly 12.5(1) or 14.0 AND the upgrade functionality is accessible.
Generated from the published advisory. Verify against your own configuration.
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 · scopedApply the vendor patch when available and restrict access to the upgrade functionality to authenticated, trusted personnel only. Monitor upgrade-related system logs for suspicious activity.
Cisco Unified CM 12.5(1a) or later / 14.0(1a) or later
- Review the Cisco Unified Communications Manager upgrade guide at https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/upgrade/12_5_1/upgrade_cucm_12_5_1.html
- Ensure you have a complete backup of your Unified CM system including the database (CSDB), as per Cisco's backup procedures
- Verify you have a valid service contract to access Cisco software updates
- Download the fixed release of Cisco Unified Communications Manager. For 12.5(1), upgrade to 12.5(1a) or later fixed version. For 14.0, upgrade to 14.0(1a) or later fixed version
- Review the Cisco upgrade procedure documentation for your specific version path
- Schedule a maintenance window as upgrades require system downtime
- Execute the upgrade following Cisco's standard upgrade procedures for Unified CM
- After upgrade, verify the system is functioning correctly and the vulnerability is remediated by reviewing the installed version
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Unified Communications Manager
Scoped from the published advisory
- Consultation4.0 h
- Implementation8.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,120.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2022-20789 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2022-20789 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
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