CVE-2018-6789: buffer overflow flaw in the SMTP listener of Exim, 400k servers may be exploited
Recently, open source mail transport agent Exim released Exim v4.90.1 to address the buffer overflow vulnerability, CVE number CVE-2018-6789. Meh Chang discovered a buffer overflow flaw in a utility function used in the SMTP listener of Exim, a mail transport agent. A remote attacker can take advantage of this flaw to cause a denial of service, or potentially the execution of arbitrary code via a specially crafted message.
Exim is a mail transfer agent (MTA) used in Unixllike operating systems. The first version was written in 1995 by Philip Hazel for use in the University of Cambridge Computing Service’s e-mailsystems. Exim is distributed under the GPL, and therefore is free to download, use and modify.
The authors of the vulnerability say there are at least 400,000 servers in the world at risk. SecurityFocus, Debian, Openwall and other issues early warning notice, the relevant information is as follows:
- SecurityFocus: http://www.securityfocus.com/bid/103049
- Exim: https://exim.org/static/doc/security/CVE-2018-6789.txt
- Debian: https://www.debian.org/security/2018/dsa-4110
- Openwall: http://openwall.com/lists/oss-security/2018/02/10/2
Please upgrade as soon as possible.
