CSL 1010 M2M 3G WiFi Module 2.2.1.4 Weak Encryption via Router.cfg

CSL 1010 M2M 3G WiFi Module firmware through 2.2.1.4 contains a weak encryption vulnerability that allows unauthenticated attackers to recover all stored secrets in plaintext by reversing a single-byte XOR cipher that uses a static key to obfuscate the configuration backup file. Attackers can trivially decrypt the Router.cfg backup file to expose web administration and telnet passwords, WPA/WPA2 pre-shared keys, PPPoE and 3G/APN credentials, and SIM identifiers including IMSI and IMEI.