#VU38233 Improper Certificate Validation in Fedora - CVE-2015-3420

Vulnerability identifier: #VU38233

Vulnerability risk: Medium

CVSSv4.0: 4.6 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2015-3420

CWE-ID: CWE-295

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Fedora
Operating systems & Components / Operating system

Vendor: Fedoraproject

Description

The vulnerability allows a remote non-authenticated attacker to perform a denial of service (DoS) attack.

The ssl-proxy-openssl.c function in Dovecot before 2.2.17, when SSLv3 is disabled, allow remote attackers to cause a denial of service (login process crash) via vectors related to handshake failures.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Fedora: 20 - 22

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External links
https://lists.fedoraproject.org/pipermail/package-announce/2015-May/157030.html
https://lists.fedoraproject.org/pipermail/package-announce/2015-May/158236.html
https://lists.fedoraproject.org/pipermail/package-announce/2015-May/158261.html
https://www.openwall.com/lists/oss-security/2015/04/27/1
https://www.openwall.com/lists/oss-security/2015/04/28/4
https://www.securityfocus.com/bid/74335
https://bugzilla.redhat.com/show_bug.cgi?id=1216057
https://dovecot.org/pipermail/dovecot/2015-April/100618.html
https://dovecot.org/pipermail/dovecot-news/2015-May/000292.html

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.