Cisco IOS XE Software Digital Signature Verification Bypass Vulnerability

Vulnerability

A vulnerability in the software image verification process of Cisco IOS XE Software allows an unauthenticated, physical attacker to bypass digital signature checks during the initial boot process. The issue stems from an improper check on the code that manages digital signature verification of system image files. Affected versions include Cisco IOS XE Software releases prior to the fixed versions listed in the advisory [1].

Exploitation

An attacker must have physical access to the affected device. The attacker can load unsigned software onto the device, and due to the bypass, the device will boot the unsigned image or execute unsigned binaries. No authentication or user interaction is required [1].

Impact

Successful exploitation allows the attacker to install and boot a malicious software image or execute unsigned binaries on the targeted device. This can lead to full compromise of the device, including arbitrary code execution and persistent control [1].

Mitigation

Cisco has released free software updates to address this vulnerability. Customers should upgrade to the fixed versions specified in the advisory [1]. No workarounds are available. Customers can obtain updates through the Cisco TAC or their service contracts [1].