Cisco SPA100 Series Analog Telephone Adapters Remote Code Execution Vulnerabilities

Vulnerability

Multiple remote code execution vulnerabilities exist in the web-based management interface of Cisco SPA100 Series Analog Telephone Adapters (ATA), including models SPA112, SPA122, SPA2102, and SPA3102. The vulnerabilities are caused by improper validation of user-supplied input. An attacker must have authenticated access to the web interface, which is enabled by default. Affected firmware versions are those prior to the fixed releases described in the Cisco security advisory [1].

Exploitation

An authenticated attacker on the same network (adjacent) can send crafted HTTP requests to the web-based management interface of an affected device. No additional user interaction is required beyond authentication. The attacker leverages input validation flaws to inject commands or trigger buffer overflows, leading to code execution.

Impact

Successful exploitation allows the attacker to execute arbitrary code with elevated privileges, effectively gaining full control of the device. This can lead to complete compromise of the ATA, including the ability to modify configuration, intercept traffic, or pivot to other network resources.

Mitigation

Cisco has released free firmware updates to address these vulnerabilities. Affected users should upgrade to the latest firmware version as specified in the Cisco Security Advisory [1]. Details on fixed releases and download instructions are available in the advisory. No workarounds are documented; the web-based management interface can be restricted to trusted networks as a general best practice.