Lenovo System Update (formerly ThinkVantage System Update) before 5.06.0034 does not properly validate CA chains during signature validation, which allows man-in-the-middle attackers to upload and execute arbitrary files via a crafted certificate.
http://www.securityfocus.com/bid/74642
http://www.ioactive.com/pdfs/Lenovo_System_Update_Multiple_Privilege_Escalations.pdf
http://support.lenovo.com/us/en/product_security/lsu_privilege