Tenda CP6 Risky Cryptographic Vulnerability in Firmware Version 11.10.00.243

A vulnerability exists in the Tenda CP6 router, specifically in firmware version 11.10.00.243. The issue arises in the 'uhttp' component, within the function 'sub_2B7D04'. During the firmware update process, this function applies an additive checksum for integrity verification. However, attackers can craft malicious firmware that mimics the checksum of legitimate updates, effectively bypassing the verification process. This flaw allows the installation of harmful firmware that could execute arbitrary code or cause a denial-of-service condition on the device.

Impact

Exploitation of this vulnerability could lead to the execution of arbitrary code on the affected device or cause a denial-of-service condition.

Reproduction

To reproduce this vulnerability, upload a firmware file that has been modified to include the same additive checksum as a legitimate update. This will bypass the integrity verification process and allow the malicious firmware to be installed on the device.