CVE-2020-5551

Toyota 2017 Model Year DCU (Display Control Unit) allows an unauthenticated attacker within Bluetooth range to cause a denial of service attack and/or execute an arbitrary command. The affected DCUs are installed in Lexus (LC, LS, NX, RC, RC F), TOYOTA CAMRY, and TOYOTA SIENNA manufactured in the regions other than Japan from Oct. 2016 to Oct. 2019. An attacker with certain knowledge on the target vehicle control system may be able to send some diagnostic commands to ECUs with some limited availability impacts; the vendor states critical vehicle controls such as driving, turning, and stopping are not affected.

Weakness

During installation, installed file permissions are set to allow anyone to modify those files.

Affected Software

Potential Mitigations

• Compartmentalize the system to have “safe” areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area.
• Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/1.html
• https://cwe.mitre.org/data/definitions/127.html
• https://cwe.mitre.org/data/definitions/81.html

References

• https://global.toyota/en/newsroom/corporate/32120629.html
• https://jvn.jp/en/vu/JVNVU99396686/index.html