Cisco Small Business RV Series Routers Management Interface Remote Command Execution and Denial of Service Vulnerabilities

Vulnerability

The web-based management interface of Cisco Small Business RV016, RV042, RV042G, RV082, RV320, and RV325 Routers (CVE-2021-1320) contains multiple vulnerabilities due to improper validation of user-supplied input. An authenticated remote attacker with valid administrator credentials can send crafted HTTP requests to exploit these flaws. Affected firmware versions are those prior to the fixed releases specified in Cisco's advisory [1].

Exploitation

To exploit these vulnerabilities, an attacker must have valid administrator credentials for the targeted router. With those credentials, the attacker sends specially crafted HTTP requests to the web-based management interface. The improper input validation in the interface allows the attacker to trigger memory corruption conditions, leading to arbitrary code execution or a full device reload [1].

Impact

Successful exploitation can allow an attacker to execute arbitrary code with root privileges on the underlying operating system, gaining full control of the device. Alternatively, the attacker can cause the router to reload, resulting in a denial of service (DoS) condition that disrupts network operations [1].

Mitigation

Cisco has released free software updates that address these vulnerabilities. Customers with affected products should upgrade to the fixed firmware versions as indicated in the Cisco Security Advisory [1]. For routers without a service contract, contact Cisco TAC for free upgrades. No workaround is available; updating firmware is the only mitigation [1].