Joxean Koret, a security researcher at Singapore-based consultancy COSEINC, has publicly revealed a series of flaws which affect major antivirus engines. The list of affected products is long and includes solutions offered by vendors such as Avast, AVG, Avira, Bitdefender, Comodo, DrWeb, ESET, F-Prot and F-Secure. The principal flaws discovered by the researcher are buffer and heap overflow vulnerabilities, local escalation of privileges and file format bugs.”]
Source: http://securityaffairs.co/wordpress/27165/hacking/serious-flaws-antivirus-engines.html