Vulnerability identifier: #VU32369

Vulnerability risk: Low

CVSSv3.1: 3.2 [CVSS:3.1/CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2015-3455

CWE-ID: CWE-20

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Squid
Server applications / IDS/IPS systems, Firewalls and proxy servers

Vendor: Squid-cache.org

Description

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

Squid 3.2.x before 3.2.14, 3.3.x before 3.3.14, 3.4.x before 3.4.13, and 3.5.x before 3.5.4, when configured with client-first SSL-bump, do not properly validate the domain or hostname fields of X.509 certificates, which allows man-in-the-middle attackers to spoof SSL servers via a valid certificate.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Squid: 3.2.0.1 - 3.2.13

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External links
http://advisories.mageia.org/MGASA-2015-0191.html
http://lists.fedoraproject.org/pipermail/package-announce/2016-May/183598.html
http://lists.opensuse.org/opensuse-updates/2015-09/msg00016.html
http://lists.opensuse.org/opensuse-updates/2016-08/msg00069.html
http://rhn.redhat.com/errata/RHSA-2015-2378.html
http://www.mandriva.com/security/advisories?name=MDVSA-2015:230
http://www.oracle.com/technetwork/topics/security/bulletinjul2015-2511963.html
http://www.oracle.com/technetwork/topics/security/linuxbulletinoct2015-2719645.html
http://www.securityfocus.com/bid/74438
http://www.securitytracker.com/id/1032221
http://www.squid-cache.org/Advisories/SQUID-2015_1.txt

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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.