usd-2018-0036 | Cisco Unified Communications Manager (CallManager)/ (likely in all versions)

Advisory ID: usd-2018-0036
CVE Number: N/A
Affected Product: Unified Communications Manager
Affected Version: (likely in all versions)
Vulnerability Type: Exposure of Sensitive Configuration Data
Security Risk: Critical
Vendor URL:
Vendor Status: Unknown


Cisco Unified Communications Manager (CallManager) is a server component for video conferencing and video telephony infrastructures. A typical setup of Cisco Unified Communications infrastructures includes one or multiple CallManagers connected to a number of video conferencing devices, such as Cisco TelePresence SX20. The TelePresence devices, which can e.g. be located in conference rooms, connect to the CallManagers to retrieve configuration files and when a video call takes place. usd discovered multiple vulnerabilities in the way these devices interact and within the CallManager itself.

First Proof of Concept

A request to the following URL will retrieve the configuration file of a specific device, containing clear-text credentials. Replace SEPXXXXXXXXX with the device name:

The resulting XML file contains clear-text credentials within the following tags:


Using these credentials the attacker can now authenticate to the target device via SSH or HTTPS. This allows the attacker to manipulate its configuration or create and download captures of network traffic. These captures can be used to eavesdrop on video and audio calls.

Second Proof of Concept

A request to the following URL will retrieve a configuration file, containing AD user credentials:

The resulting XML file contains clear-text credentials within the following tags:


This data may provide attackers with access to a valid domain user.

Third Proof of Concept

A request to the following URL served up a firmware package:

Note: This file name may be different on other CallManagers.
The XML files mentioned above include references to these files names, such as:s52020ce9_4_1-6ae80e1f2ee.pkg
Knowledge of the firmware allows attackers to search for additional vulnerabilities within the software.


To prevent unauthorized access to this data the CallManager needs to properly authenticate client devices. Additionally, the CallManager should utilize HTTPS for transport encryption.


  • 2018-10-31 Advisory has been sent to
  • 2018-11-09 extended public disclosure deadline to 2019-01-23
  • 2019-01-23 Security advisory released


This security vulnerabilities were discovered by Marcus Gruber and Maximilian Boehner of usd AG.


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to usd AG

In accordance with usd AG’s Responsible Disclosure Policy, all vendors have been notified of the existence of these vulnerabilities.


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