RS9116 SDK EUVD-2026-30381

RS9116 wireless module must be operating in power save mode-a feature typically enabled by default or explicitly configured in battery-operated IoT devices to reduce power consumption. Attacker must be within adjacent network range (WiFi or Bluetooth proximity, typically 10-100 meters depending on environment) during cryptographic handshake operations when the HRNG is invoked for key material generation. User interaction is required per CVSS vector (UI:P), suggesting exploitation timing depends on when legitimate users or applications trigger connection establishment or re-keying events. Attack complexity is low (AC:L) but timing is constrained (AT:P), meaning the attacker must capture specific protocol exchanges during the narrow window when predictable entropy is used. Successful exploitation requires protocol-level knowledge of WiFi or Bluetooth cryptographic handshakes and ability to implement the timing-based prediction algorithm specific to the RS9116 HRNG implementation.

Real-world risk is MODERATE-HIGH despite the 7.4 CVSS score. The CVSS 4.0 vector indicates adjacent network access (AV:A) requiring user interaction (UI:P) with low attack complexity (AC:L), while privileged access is not required (PR:N). Attack conditions require physical proximity to the wireless device and user interaction, limiting mass exploitation-reflected in SSVC assessment of non-automatable, no current exploitation. However, SSVC technical impact is marked 'total' because predictable cryptographic material can completely undermine confidentiality and integrity. The vulnerability's severity is contextual: critical for devices handling sensitive data over WiFi/Bluetooth (medical IoT, industrial sensors, smart home controllers), but lower risk for applications with defense-in-depth transport security. Missing EPSS score and absence from CISA KEV suggest no widespread exploitation activity, but cryptographic vulnerabilities can be silently exploited for targeted attacks. Patch availability mitigates long-term risk, though embedded device update challenges persist.

An attacker positions themselves within WiFi range (adjacently on the same network segment) of a battery-powered industrial sensor running RS9116 SDK 2.13.1 in power save mode. When the sensor establishes a new encrypted connection, the attacker captures the WPA2 handshake or Bluetooth pairing exchange. Leveraging knowledge of the HRNG's predictable timing behavior in power save mode, the attacker computes likely nonce values generated during the handshake, reducing the keyspace from cryptographically strong (2^128) to a feasible brute-force range. With publicly available tools adapted for the known timing weakness, they derive the session key and decrypt all subsequent wireless traffic, gaining access to proprietary sensor data or control commands.