Cisco Unified Communications Manager Static SSH Credentials Vulnerability

TL;DR 📌

• A vulnerability in Cisco Unified Communications Manager (Unified CM) and Cisco Unified Communications Manager Session Management Edition (Unified CM SME) could allow an unauthenticated, remote attacker to log in to an affected device using the root account, which has default, static credentials that cannot be changed or deleted. This vulnerability is due to the presence of static user credentials for…
• No fixed release listed yet; apply mitigations and monitor.
• Workarounds are documented in the advisory.
• CVEs: CVE-2025-20309.

What happened 🕵️‍♂️

A vulnerability in Cisco Unified Communications Manager (Unified CM) and Cisco Unified Communications Manager Session Management Edition (Unified CM SME) could allow an unauthenticated, remote attacker to log in to an affected device using the root account, which has default, static credentials that cannot be changed or deleted.

This vulnerability is due to the presence of static user credentials for the root account that are reserved for use during development. An attacker could exploit this vulnerability by using the account to log in to an affected system. A successful exploit could allow the attacker to log in to the affected system and execute arbitrary commands as the root user.

Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.

Affected products 🖥️

This vulnerability affects Cisco Unified CM and Unified CM SME Engineering Special (ES) releases 15.0.1.13010-1 through 15.0.1.13017-1, regardless of device configuration.

Note: ES releases are limited fix releases that are distributed only by the Cisco Technical Assistance Center (TAC).

For information about which Cisco software releases are vulnerable, see the Fixed Software ["#fs"] section of this advisory.

Fixed software 🔧

Upgrade to the first fixed release in your train (or later):

Workarounds 🧯

There are no workarounds that address this vulnerability.

Risk in context 🎯

Use vendor CVSS for prioritization. Consider exposure and asset criticality.

Fast facts ⚡

• Advisory: cisco-sa-cucm-ssh-m4UBdpE7
• Initial release: 2025-07-02T16:00:00 UTC
• Last updated: 2025-07-02T16:00:00 UTC

For leadership 🧭

Executive summary. Risk is Critical (CVSS 10.0) for Cisco, Cisco Unified Communications Manager. Vendor fixes are available; prioritize upgrade within 48–72 hours based on environment risk.

Why it matters (exposure drivers):

• Potential service impact and security exposure depend on deployment topology and access paths.
• Treat internet-exposed or multi-tenant management nodes as higher risk.
• Ensure monitoring for abnormal auth/config events until upgrades complete.

Remediation & timing:

• Upgrade to the first fixed release per the table above; schedule an approved change window within 48–72 hours.
• Change risk: low-to-moderate (standard vendor patch). Validate backups and rollback plan.

Now / Next / Later:

• Now: Confirm exposure, identify affected versions, and enable monitoring/alerts.
• Next: Patch according to the fixed software table; verify service health post-change.
• Later: Add control checks to build pipeline/CMDB to block drift to vulnerable trains.