Last year, during a routine code review, Qualys discovered a Remote Command Execution (RCE) vulnerability in the Exim Mail Transfer Agent (MTA) mail server. The vulnerability has been dubbed "The Return of the WIZard" and is listed under CVE-2019-10149. The RCE vulnerability exists in Exim mail server versions 4.87 to 4.91 (inclusive). When exploited the vulnerability allows an attacker to execute arbitrary commands with root privileges.βββββο»Ώβο»Ώββββββο»Ώο»Ώβο»Ώβββββββββο»Ώββββββο»Ώββββββο»Ώβββββββο»Ώβο»Ώββββββο»Ώββββββο»Ώβββο»Ώββββο»Ώβββββββο»Ώο»Ώββββββο»Ώββββββββββο»Ώβββββββββββββββο»Ώβββββββββββο»Ώβββο»Ώβββο»Ώβββο»Ώβο»Ώβο»Ώββββο»Ώο»Ώββο»Ώο»Ώββββββο»Ώββο»Ώββββββββο»Ώββο»Ώβββο»Ώβο»Ώβο»Ώββββο»Ώββο»Ώβο»Ώββββββο»Ώββββββο»Ώβββο»Ώββββο»Ώββο»Ώβο»Ώβο»Ώβββο»Ώββββββββββββο»Ώο»Ώββο»Ώο»Ώββββββο»Ώββο»Ώββββββββο»Ώββο»Ώββββο»Ώο»Ώβββββββββββββο»Ώββββο»Ώο»Ώββο»Ώβββο»Ώο»Ώβββββββββο»Ώο»Ώββο»Ώβββο»Ώβββββββο»Ώβο»Ώββββββο»Ώββο»Ώβββββββο»Ώββββββββο»Ώο»Ώββο»Ώββο»Ώβο»Ώβββββββββο»Ώο»Ώββββο»Ώβο»Ώβββββο»Ώβββββββββο»Ώβββο»Ώβββββββο»Ώββββββββο»Ώββββββο»Ώβββο»Ώββββο»Ώο»Ώββο»Ώββββββο»Ώβββο»Ώββββο»Ώββββββο»Ώβββο»Ώβο»Ώβο»Ώβββο»Ώβββο»Ώβββββββο»Ώο»Ώβββββββο»Ώβββο»Ώο»Ώβββο»Ώβο»Ώβο»Ώβο»Ώβββββββο»Ώβββββββο»Ώο»Ώββο»Ώβββββββββο»Ώβββββββββο»Ώββββββββο»Ώββββββββββο»Ώβββββββο»Ώββββββββο»Ώο»Ώβββο»Ώβββββο»Ώβββββββο»Ώβο»Ώβββββββββο»Ώβο»Ώβββββββββο»Ώβββο»Ώββββο»Ώββββββο»Ώββββββββο»Ώο»Ώβο»Ώββββο»Ώββββββο»Ώβββο»Ώβββββββββββββββο»Ώβββο»Ώβββββββο»Ώββββββββο»Ώββο»Ώβββββββββο»Ώβββββββββββββο»Ώβββο»Ώβββββββο»Ώββββββββο»Ώο»Ώβββο»Ώβββββο»Ώβββββββο»Ώβο»Ώβββββββββο»Ώβο»Ώβββββββββο»Ώβββο»Ώββββββββο»Ώο»Ώβββββο»Ώββββββββββββο»Ώββββο»Ώβο»Ώβο»Ώββο»Ώββββββο»Ώβββββββο»Ώβββο»Ώβββββββο»Ώββββββββο»Ώββββο»Ώββββββββββο»Ώββββββο»Ώββββββββο»Ώββββββο»Ώββββββββο»Ώο»Ώβββο»Ώβββββο»Ώβββββββο»Ώβο»Ώβββββββββο»Ώβο»Ώβββββββββο»Ώβββο»Ώβββο»Ώβββββββο»Ώβββββββο»Ώβββββββββββββο»Ώβββο»Ώβο»Ώβββο»Ώβββββββββββο»Ώβββο»Ώβββββββο»Ώββββββββο»Ώββο»Ώβββββββο»Ώβββο»Ώβββο»Ώο»Ώο»Ώβββββββββο»Ώβο»Ώβββββββββο»Ώββββο»Ώββο»Ώο»Ώββββββο»Ώβββο»Ώβββο»Ώβββο»Ώβο»Ώβββββο»Ώβο»Ώβββββββββο»Ώβββββββββββο»Ώββββββββββββο»Ώββο»Ώββββββββο»Ώββο»Ώβββο»Ώβο»Ώβο»Ώββββο»Ώββο»Ώβο»Ώββββββο»Ώββββββο»Ώβββο»Ώββββο»Ώββο»Ώβο»Ώβο»Ώβββο»Ώββββββββββββο»Ώο»Ώβββββββββββββο»Ώο»Ώββββο»Ώβο»Ώβββββο»Ώβββββββββο»Ώβββο»Ώβββββββο»Ώββββββββο»Ώββββββο»Ώβββο»Ώββββο»Ώο»Ώββο»Ώββββββο»Ώβββο»Ώββββο»Ώββββββο»Ώβββββββο»Ώβββο»Ώβββο»Ώβββββββο»Ώο»Ώβββββββο»Ώβββο»Ώο»Ώβββο»Ώβββββο»Ώβββββββο»Ώβββββββο»Ώο»Ώββο»Ώβββββββββο»Ώβββββββββο»Ώββββββββο»Ώββββββββββο»Ώβββββββο»Ώββββββββο»Ώο»Ώβββο»Ώβββββο»Ώβββββββο»Ώβο»Ώβββββββββο»Ώβο»Ώβββββββββο»Ώβββο»Ώββββο»Ώββββββο»Ώββββββββο»Ώο»Ώβο»Ώββββο»Ώββββββο»Ώβββο»Ώβββββββββββββββο»Ώβββο»Ώβββββββο»Ώββββββββο»Ώββο»Ώβββββββββο»Ώβββββββββββββο»Ώβββο»Ώβββββββο»Ώββββββββο»Ώο»Ώβββο»Ώβββββο»Ώβββββββο»Ώβο»Ώβββββββββο»Ώβο»Ώβββββββββο»Ώβββο»Ώββββββββο»Ώο»Ώβββββο»Ώββββββββββββο»Ώββββο»Ώβο»Ώβο»Ώββο»Ώββββββο»Ώβββββββο»Ώβββο»Ώβββββββο»Ώββββββββο»Ώββββο»Ώββββββββββο»Ώββββββο»Ώββββββββο»Ώββββββο»Ώββββββββο»Ώο»Ώβββο»Ώβββββο»Ώβββββββο»Ώβο»Ώβββββββββο»Ώβο»Ώβββββββββο»Ώβββο»Ώβββο»Ώβββββββο»Ώβββββββο»Ώβββββββββββββο»Ώβββο»Ώβο»Ώβββο»Ώβββββββββββο»Ώβββο»Ώβββββββο»Ώββββββββο»Ώββο»Ώβββββββο»Ώβββο»Ώβββββββο»Ώβββββββο»Ώβββο»Ώβο»Ώβο»Ώβββββββββο»Ώβο»Ώβββββββο»Ώβββββββο»Ώο»Ώββο»Ώβββο»Ώββββββββο»Ώββββββο»Ώβο»Ώβββββββββββββββββο»Ώο»Ώβ
The Exim mail server is ubiquitous on the internet. More than 50% of public-facing mail servers run Exim MTA and over 500,000 Exim mail servers exist on the internet. The severity of the vulnerability, coupled with its large presence on the internet makes the potential impact of this exploit quite extreme. While this exploit was patched over a year ago, many public-facing Exim mail servers are still vulnerable. The vulnerability has been utilized as recent as October 2020 by the Russian state-sponsored threat actor known as Berserk Bear.βββββο»Ώβο»Ώββββββο»Ώο»Ώβο»Ώβββββββββο»Ώββββββο»Ώββββββο»Ώβββββββο»Ώβο»Ώββββββο»Ώββββββο»Ώβββο»Ώββββο»Ώβββββββο»Ώο»Ώββββββο»Ώββββββββββο»Ώβββββββββββββββο»Ώβββββββββββο»Ώβββο»Ώβββο»Ώβββο»Ώβο»Ώβο»Ώββββο»Ώο»Ώββο»Ώο»Ώββββββο»Ώββο»Ώββββββββο»Ώββο»Ώβββο»Ώβο»Ώβο»Ώββββο»Ώββο»Ώβο»Ώββββββο»Ώββββββο»Ώβββο»Ώββββο»Ώββο»Ώβο»Ώβο»Ώβββο»Ώββββββββββββο»Ώο»Ώββο»Ώο»Ώββββββο»Ώββο»Ώββββββββο»Ώββο»Ώββββο»Ώο»Ώβββββββββββββο»Ώββββο»Ώο»Ώββο»Ώβββο»Ώο»Ώβββββββββο»Ώο»Ώββο»Ώβββο»Ώβββββββο»Ώβο»Ώββββββο»Ώββο»Ώβββββββο»Ώββββββββο»Ώο»Ώββο»Ώββο»Ώβο»Ώβββββββββο»Ώο»Ώββββο»Ώβο»Ώβββββο»Ώβββββββββο»Ώβββο»Ώβββββββο»Ώββββββββο»Ώββββββο»Ώβββο»Ώββββο»Ώο»Ώββο»Ώββββββο»Ώβββο»Ώββββο»Ώββββββο»Ώβββο»Ώβο»Ώβο»Ώβββο»Ώβββο»Ώβββββββο»Ώο»Ώβββββββο»Ώβββο»Ώο»Ώβββο»Ώβο»Ώβο»Ώβο»Ώβββββββο»Ώβββββββο»Ώο»Ώββο»Ώβββββββββο»Ώβββββββββο»Ώββββββββο»Ώββββββββββο»Ώβββββββο»Ώββββββββο»Ώο»Ώβββο»Ώβββββο»Ώβββββββο»Ώβο»Ώβββββββββο»Ώβο»Ώβββββββββο»Ώβββο»Ώββββο»Ώββββββο»Ώββββββββο»Ώο»Ώβο»Ώββββο»Ώββββββο»Ώβββο»Ώβββββββββββββββο»Ώβββο»Ώβββββββο»Ώββββββββο»Ώββο»Ώβββββββββο»Ώβββββββββββββο»Ώβββο»Ώβββββββο»Ώββββββββο»Ώο»Ώβββο»Ώβββββο»Ώβββββββο»Ώβο»Ώβββββββββο»Ώβο»Ώβββββββββο»Ώβββο»Ώβββο»Ώβββο»Ώβββββββο»Ώβο»Ώβο»Ώββββο»Ώβββο»Ώο»Ώβο»Ώβο»Ώββββββο»Ώββο»Ώβββο»Ώβββββββο»Ώβββο»Ώβββββββο»Ώββββββββο»Ώββββο»Ώββββββββββο»Ώββββββο»Ώββββββββο»Ώββββββο»Ώββββββββο»Ώο»Ώβββο»Ώβββββο»Ώβββββββο»Ώβο»Ώβββββββββο»Ώβο»Ώβββββββββο»Ώβββο»Ώββββο»Ώο»Ώβο»Ώβββββββο»Ώββββο»Ώο»Ώβο»Ώβο»Ώβββββο»Ώβββββο»Ώβββββο»Ώβββββββββββο»Ώβββο»Ώβββββββο»Ώββββββββο»Ώββο»Ώβββββββο»Ώβββο»Ώβββο»Ώο»Ώο»Ώβββββββββο»Ώβο»Ώβββββββββο»Ώββββο»Ώββο»Ώο»Ώββββββο»Ώβββο»Ώβββο»Ώβββο»Ώβο»Ώβββββο»Ώβο»Ώβββββββββο»Ώβββββββββββο»Ώββββββββββββο»Ώββο»Ώββββββββο»Ώββο»Ώβββο»Ώβο»Ώβο»Ώββββο»Ώββο»Ώβο»Ώββββββο»Ώββββββο»Ώβββο»Ώββββο»Ώββο»Ώβο»Ώβο»Ώβββο»Ώββββββββββββο»Ώο»Ώβββββββββββββο»Ώο»Ώββββο»Ώβο»Ώβββββο»Ώβββββββββο»Ώβββο»Ώβββββββο»Ώββββββββο»Ώββββββο»Ώβββο»Ώββββο»Ώο»Ώββο»Ώββββββο»Ώβββο»Ώββββο»Ώββββββο»Ώβββββββο»Ώβββο»Ώβββο»Ώβββββββο»Ώο»Ώβββββββο»Ώβββο»Ώο»Ώβββο»Ώβββββο»Ώβββββββο»Ώβββββββο»Ώο»Ώββο»Ώβββββββββο»Ώβββββββββο»Ώββββββββο»Ώββββββββββο»Ώβββββββο»Ώββββββββο»Ώο»Ώβββο»Ώβββββο»Ώβββββββο»Ώβο»Ώβββββββββο»Ώβο»Ώβββββββββο»Ώβββο»Ώββββο»Ώββββββο»Ώββββββββο»Ώο»Ώβο»Ώββββο»Ώββββββο»Ώβββο»Ώβββββββββββββββο»Ώβββο»Ώβββββββο»Ώββββββββο»Ώββο»Ώβββββββββο»Ώβββββββββββββο»Ώβββο»Ώβββββββο»Ώββββββββο»Ώο»Ώβββο»Ώβββββο»Ώβββββββο»Ώβο»Ώβββββββββο»Ώβο»Ώβββββββββο»Ώβββο»Ώβββο»Ώβββο»Ώβββββββο»Ώβο»Ώβο»Ώββββο»Ώβββο»Ώο»Ώβο»Ώβο»Ώββββββο»Ώββο»Ώβββο»Ώβββββββο»Ώβββο»Ώβββββββο»Ώββββββββο»Ώββββο»Ώββββββββββο»Ώββββββο»Ώββββββββο»Ώββββββο»Ώββββββββο»Ώο»Ώβββο»Ώβββββο»Ώβββββββο»Ώβο»Ώβββββββββο»Ώβο»Ώβββββββββο»Ώβββο»Ώββββο»Ώο»Ώβο»Ώβββββββο»Ώββββο»Ώο»Ώβο»Ώβο»Ώβββββο»Ώβββββο»Ώβββββο»Ώβββββββββββο»Ώβββο»Ώβββββββο»Ώββββββββο»Ώββο»Ώβββββββο»Ώβββο»Ώβββββββο»Ώβββββββο»Ώβββο»Ώβο»Ώβο»Ώβββββββββο»Ώβο»Ώβββββββο»Ώβββββββο»Ώο»Ώββο»Ώβββο»Ώββββββββο»Ώββββββο»Ώβο»Ώβββββββββββββββββο»Ώο»Ώβ
Check out Cyborg Security's Threat Hunt Deep Dives Ep. 1: Return of the WIZard - Exim MTA RCE (CVE-2019-10149) to learn more about this vulnerability.βββββο»Ώβο»Ώββββββο»Ώο»Ώβο»Ώβββββββββο»Ώββββββο»Ώββββββο»Ώβββββββο»Ώβο»Ώββββββο»Ώββββββο»Ώβββο»Ώββββο»Ώβββββββο»Ώο»Ώββββββο»Ώββββββββββο»Ώβββββββββββββββο»Ώβββββββββββο»Ώβββο»Ώβββο»Ώβββο»Ώβο»Ώβο»Ώββββο»Ώο»Ώββο»Ώο»Ώββββββο»Ώββο»Ώββββββββο»Ώββο»Ώβββο»Ώβο»Ώβο»Ώββββο»Ώββο»Ώβο»Ώββββββο»Ώββββββο»Ώβββο»Ώββββο»Ώββο»Ώβο»Ώβο»Ώβββο»Ώββββββββββββο»Ώο»Ώββο»Ώο»Ώββββββο»Ώββο»Ώββββββββο»Ώββο»Ώββββο»Ώο»Ώβββββββββββββο»Ώββββο»Ώο»Ώββο»Ώβββο»Ώο»Ώβββββββββο»Ώο»Ώββο»Ώβββο»Ώβββββββο»Ώβο»Ώββββββο»Ώββο»Ώβββββββο»Ώββββββββο»Ώο»Ώββο»Ώββο»Ώβο»Ώβββββββββο»Ώο»Ώββββο»Ώβο»Ώβββββο»Ώβββββββββο»Ώβββο»Ώβββββββο»Ώββββββββο»Ώββββββο»Ώβββο»Ώββββο»Ώο»Ώββο»Ώββββββο»Ώβββο»Ώββββο»Ώββββββο»Ώβββο»Ώβο»Ώβο»Ώβββο»Ώβββο»Ώβββββββο»Ώο»Ώβββββββο»Ώβββο»Ώο»Ώβββο»Ώβο»Ώβο»Ώβο»Ώβββββββο»Ώβββββββο»Ώο»Ώββο»Ώβββββββββο»Ώβββββββββο»Ώββββββββο»Ώββββββββββο»Ώβββββββο»Ώββββββββο»Ώο»Ώβββο»Ώβββββο»Ώβββββββο»Ώβο»Ώβββββββββο»Ώβο»Ώβββββββββο»Ώβββο»Ώββββο»Ώββββββο»Ώββββββββο»Ώο»Ώβο»Ώββββο»Ώββββββο»Ώβββο»Ώβββββββββββββββο»Ώβββο»Ώβββββββο»Ώββββββββο»Ώββο»Ώβββββββββο»Ώβββββββββββββο»Ώβββο»Ώβββββββο»Ώββββββββο»Ώο»Ώβββο»Ώβββββο»Ώβββββββο»Ώβο»Ώβββββββββο»Ώβο»Ώβββββββββο»Ώβββο»Ώβββββο»Ώβο»Ώββββο»Ώβββββββο»Ώο»Ώβο»Ώββββο»Ώββο»Ώβββββββββο»Ώβο»Ώβο»Ώβββο»Ώβββββο»Ώβββο»Ώβββββββο»Ώββββββββο»Ώββββο»Ώββββββββββο»Ώββββββο»Ώββββββββο»Ώββββββο»Ώββββββββο»Ώο»Ώβββο»Ώβββββο»Ώβββββββο»Ώβο»Ώβββββββββο»Ώβο»Ώβββββββββο»Ώβββο»Ώβββββο»Ώβο»Ώβββββββββββββο»Ώββο»Ώο»Ώβββο»Ώββββββββββο»Ώο»Ώβββββββββββββο»Ώβββο»Ώβββββββο»Ώββββββββο»Ώββο»Ώβββββββο»Ώβββο»Ώβββο»Ώο»Ώο»Ώβββββββββο»Ώβο»Ώβββββββββο»Ώββββο»Ώββο»Ώο»Ώββββββο»Ώβββο»Ώβββο»Ώβββο»Ώβο»Ώβββββο»Ώβο»Ώβββββββββο»Ώβββββββββββο»Ώββββββββββββο»Ώββο»Ώββββββββο»Ώββο»Ώβββο»Ώβο»Ώβο»Ώββββο»Ώββο»Ώβο»Ώββββββο»Ώββββββο»Ώβββο»Ώββββο»Ώββο»Ώβο»Ώβο»Ώβββο»Ώββββββββββββο»Ώο»Ώβββββββββββββο»Ώο»Ώββββο»Ώβο»Ώβββββο»Ώβββββββββο»Ώβββο»Ώβββββββο»Ώββββββββο»Ώββββββο»Ώβββο»Ώββββο»Ώο»Ώββο»Ώββββββο»Ώβββο»Ώββββο»Ώββββββο»Ώβββββββο»Ώβββο»Ώβββο»Ώβββββββο»Ώο»Ώβββββββο»Ώβββο»Ώο»Ώβββο»Ώβββββο»Ώβββββββο»Ώβββββββο»Ώο»Ώββο»Ώβββββββββο»Ώβββββββββο»Ώββββββββο»Ώββββββββββο»Ώβββββββο»Ώββββββββο»Ώο»Ώβββο»Ώβββββο»Ώβββββββο»Ώβο»Ώβββββββββο»Ώβο»Ώβββββββββο»Ώβββο»Ώββββο»Ώββββββο»Ώββββββββο»Ώο»Ώβο»Ώββββο»Ώββββββο»Ώβββο»Ώβββββββββββββββο»Ώβββο»Ώβββββββο»Ώββββββββο»Ώββο»Ώβββββββββο»Ώβββββββββββββο»Ώβββο»Ώβββββββο»Ώββββββββο»Ώο»Ώβββο»Ώβββββο»Ώβββββββο»Ώβο»Ώβββββββββο»Ώβο»Ώβββββββββο»Ώβββο»Ώβββββο»Ώβο»Ώββββο»Ώβββββββο»Ώο»Ώβο»Ώββββο»Ώββο»Ώβββββββββο»Ώβο»Ώβο»Ώβββο»Ώβββββο»Ώβββο»Ώβββββββο»Ώββββββββο»Ώββββο»Ώββββββββββο»Ώββββββο»Ώββββββββο»Ώββββββο»Ώββββββββο»Ώο»Ώβββο»Ώβββββο»Ώβββββββο»Ώβο»Ώβββββββββο»Ώβο»Ώβββββββββο»Ώβββο»Ώβββββο»Ώβο»Ώβββββββββββββο»Ώββο»Ώο»Ώβββο»Ώββββββββββο»Ώο»Ώβββββββββββββο»Ώβββο»Ώβββββββο»Ώββββββββο»Ώββο»Ώβββββββο»Ώβββο»Ώβββββββο»Ώβββββββο»Ώβββο»Ώβο»Ώβο»Ώβββββββββο»Ώβο»Ώβββββββο»Ώβββββββο»Ώο»Ώββο»Ώβββο»Ώββββββββο»Ώββββββο»Ώβο»Ώβββββββββββββββββο»Ώο»Ώβ
https://nvd.nist.gov/vuln/detail/CVE-2019-10149
https://www.qualys.com/2019/06/05/cve-2019-10149/return-wizard-rce-exim.txt
https://www.scythe.io/library/threatthursday-bersek-bearhttps://us-cert.cisa.gov/ncas/alerts/aa20-296a
Initial access brokers sell information about or access to compromised computers. Here's how to threat hunt for a known attack behavior involving PowerShell that's used by a prolific initial access broker.
In July 2025 threat actors exploited zero-day vulnerabilities in on-premises Microsoft SharePoint servers in an incident known as ToolShell. In this case study, we conduct a threat hunt for ToolShell-related activity.
Guided Threat Hunts offers a library ofΒ Pivot Queries for hundreds of hunt packages that enable your threat hunters and analysts to overcome uncertainty and boost productivity. Guided Threat Hunts is a set of packages that assists users modify their result set to decide their next step and filter out noise from extraneous results.Β Β
Stay informed with our weekly executive update, sending you the latest news and timely data on the threats, risks, and regulations affecting your organization.