Input validation error in Dovecot

1) Input validation error

EUVDB-ID: #VU43025

Risk: Medium

CVSSv3.1: 5.7 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2011-4318

CWE-ID: CWE-20 - Improper input validation

Exploit availability: No

Description

The vulnerability allows a remote non-authenticated attacker to read and manipulate data.

Dovecot 2.0.x before 2.0.16, when ssl or starttls is enabled and hostname is used to define the proxy destination, does not verify that the server hostname matches a domain name in the subject's Common Name (CN) of the X.509 certificate, which allows man-in-the-middle attackers to spoof SSL servers via a valid certificate for a different hostname.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Dovecot: 2.0.0 - 2.0.15

External links

http://hg.dovecot.org/dovecot-2.0/rev/5e9eaf63a6b1
http://rhn.redhat.com/errata/RHSA-2013-0520.html
http://secunia.com/advisories/46886
http://secunia.com/advisories/52311
http://www.dovecot.org/list/dovecot-news/2011-November/000200.html
http://www.openwall.com/lists/oss-security/2011/11/18/5
http://www.openwall.com/lists/oss-security/2011/11/18/7
http://bugs.gentoo.org/show_bug.cgi?id=390887
http://bugzilla.redhat.com/show_bug.cgi?id=754980

Q & A

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.