Exim dnsdb Out-Of-Bounds Read Information Disclosure Vulnerability. This vulnerability allows network-adjacent attackers to disclose sensitive information on affected installations of Exim. Authentication is not required to exploit this vulnerability. The specific flaw exists within the smtp service, which listens on TCP port 25 by default. The issue results from the lack of proper validation of user-supplied data, which can result in a read past the end of an allocated buffer. An attacker can leverage this in conjunction with other vulnerabilities to execute arbitrary code in the context of the service account. Was ZDI-CAN-17643.