Cisco SPA100 Series Analog Telephone Adapters Remote Code Execution Vulnerabilities

Vulnerability

The vulnerability resides in the web-based management interface of Cisco SPA100 Series Analog Telephone Adapters (ATAs). Improper validation of user-supplied input in the interface allows an authenticated, adjacent attacker to send crafted HTTP requests that trigger a buffer overflow or similar memory corruption. Affected versions include all firmware releases prior to the Cisco-provided fix. The web-based management interface is enabled by default [1].

Exploitation

An attacker must first authenticate to the web-based management interface, requiring valid credentials, and be adjacent to the target device on the same Layer 2 network segment (e.g., via Ethernet or a local wireless segment). After authentication, the attacker sends specially crafted requests to the affected endpoint, triggering improper input handling that leads to memory corruption [1].

Impact

Successful exploitation allows the attacker to execute arbitrary code on the device with elevated privileges, potentially gaining full control over the ATA. This could lead to disclosure of sensitive information, modification of device configuration, denial of service, or use of the ATA as a pivot point for further attacks on the network [1].

Mitigation

Cisco has released free firmware updates to address this vulnerability. Users should upgrade to the fixed version as indicated in the Cisco Security Advisory. If upgrading is not immediately possible, restrict access to the web-based management interface to trusted administrative networks only. No workarounds are documented that fully mitigate the vulnerability without patching [1].