Cisco Small Business RV110W, RV130, RV130W, and RV215W Routers IPSec VPN Server Authentication Bypass Vulnerability

Vulnerability

A vulnerability in the IPSec VPN Server authentication of Cisco Small Business RV110W, RV130, RV130W, and RV215W routers allows an unauthenticated, remote attacker to bypass authentication controls. The issue stems from improper implementation of the password validation algorithm. Affected devices must have the IPSec VPN Server feature enabled (configured via VPN > IPSec VPN Server > Setup). Cisco has not released software updates addressing this vulnerability [1].

Exploitation

An attacker can exploit this vulnerability by sending crafted credentials during the IPSec VPN login process from an affected device. No prior authentication or user interaction is required; the attacker only needs network access to the VPN server. The improper password validation algorithm allows the crafted credentials to be accepted, bypassing normal authentication [1].

Impact

Successful exploitation grants the attacker access to the IPSec VPN network. Depending on the crafted credentials used, the attacker may obtain privileges equivalent to an administrative user, potentially leading to full control of the VPN and connected resources [1].

Mitigation

As of the advisory publication date (September 8, 2022), Cisco has not released software updates to fix this vulnerability. No workarounds are available. Users are advised to monitor Cisco's security advisories for future updates. If the IPSec VPN Server is not required, disabling it may reduce exposure [1].