Software Engineering Institute

CWE-23: Relative Path Traversal

Emerson Network Power Avocent MergePoint Unity 2016 (MPU2016) KVM and possibly other model switches running firmware version 1.9.16473 and possibly previous versions contain a directory traversal vulnerability. This vulnerability is caused from a failure to sanitize the user-supplied input parameter "filename" within the download.php file. An attacker can use directory traversal to download critical files such as /etc/passwd to obtain the credentials for the device.

It has been reported that Emerson Network Power Avocent MergePoint Unity KVM firmware version 1.2.3 through 1.10.10 are affected.

It also has been reported that this firmware is shared among the entire MergePoint Unity KVM switch line.

• MPU104E
• MPU108E
• MPU1016
• MPU2016
• MPU2032
• MPU4032
• MPU8032

A remote authenticated attacker can download the configuration files of the device and use the obtained administrator credentials to access the interface. The attacker may then modify the settings of the device with unrestricted access.

Update
Users are advised to upgrade to Emerson Network Power Avocent MergePoint Unity KVM firmware version 1.14 or 1.18 or higher.

Restrict access to the KVM switch interface

Restrict access to the MPU2016 KVM switch web interface to trusted networks. If possible, configure management and transit networks for separate VLANs, or restrict access to the device using IP access lists.