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

Vulnerability

CVE-2021-1327 describes multiple vulnerabilities in the web-based management interface of Cisco Small Business RV016, RV042, RV042G, RV082, RV320, and RV325 routers. These flaws stem from improper validation of user-supplied input, allowing an authenticated remote attacker to send specially crafted HTTP requests to trigger arbitrary code execution or a denial-of-service condition. The affected devices run firmware versions prior to the fixed releases detailed in the Cisco advisory [1].

Exploitation

An attacker must possess valid administrator credentials for the target device. With those credentials, the attacker can craft malicious HTTP requests and send them to the web-based management interface. No additional user interaction is required, and the attack is network-based [1].

Impact

Successful exploitation grants the attacker arbitrary code execution as the root user on the underlying operating system, leading to full compromise of confidentiality, integrity, and availability. Alternatively, the attacker can trigger a device reload, causing a denial-of-service (DoS) condition [1].

Mitigation

Cisco has released free software updates to address these vulnerabilities. Affected users should upgrade to the latest firmware version for their router model as specified in the Cisco Security Advisory [1]. No workarounds are available; upgrading is the only remediation. Customers with service contracts can obtain updates through normal channels, while those without should contact Cisco TAC for assistance [1].