This security advisory describes one critical risk vulnerability.
Exploit availability: YesDescription
The vulnerability allows a remote attacker to execute arbitrary shell commands on the target system.
The vulnerability exists due to improper validation of user-supplied input passed within the
smtp_mailaddr() function. A remote unauthenticated attacker can send a specially crafted MAIL FROM command and execute arbitrary OS commands on the target system with root privileges.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.Mitigation
Install updates from vendor's website.Vulnerable software versions
OpenSMTPD: 6.4.0, 6.4.0p1, 6.4.0p2, 6.4.1, 6.4.1p1, 6.4.1p2, 6.4.2, 6.4.2p1, 6.6.0, 6.6.0p1, 6.6.1, 6.6.1p1CPE
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.
How the attacker can exploit this vulnerability?
The attacker would have to send a specially crafted request to the affected application in order to exploit this vulnerability.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability. However, a fully functional exploit for this vulnerability is available.