Cisco RV110W, RV130W, and RV215W Routers Management Interface Buffer Overflow Vulnerability

Vulnerability

The vulnerability resides in the web-based management interface of the Cisco RV110W Wireless-N VPN Firewall, RV130W Wireless-N Multifunction VPN Router, and RV215W Wireless-N VPN Router. It is due to improper boundary restrictions on user-supplied input in the Guest user feature of the interface. This buffer overflow condition can be triggered without authentication. The affected firmware versions are those prior to updates provided for the RV130W; the RV110W and RV215W have no fix available [1].

Exploitation

An unauthenticated, remote attacker can exploit this vulnerability by sending specially crafted malicious requests to the targeted device's web-based management interface. The attacker does not need prior authentication or network special privileges other than network access to the management interface. The sequence of steps involves crafting a request that exceeds the expected buffer size in the Guest user feature, thereby triggering a buffer overflow [1].

Impact

Successful exploitation allows the attacker to cause the device to stop responding, resulting in a denial of service condition, or to execute arbitrary code with the privileges of the affected process. This can lead to complete compromise of the router's management functions and potentially enable further attacks on the network [1].

Mitigation

For the Cisco RV130W, Cisco has released free firmware updates that address the vulnerability. Users should upgrade to the fixed firmware version as indicated in the Cisco security advisory [1]. For the Cisco RV110W and RV215W, Cisco has not and will not release firmware updates; these devices are end-of-life and no fix is available. The only mitigation is to replace the devices or restrict access to the management interface to trusted networks only [1].