Input validation error in Squid-cache Squid

1) Input validation error

EUVDB-ID: #VU32273

Risk: Medium

CVSSv3.1: 6.5 [AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2016-4556

CWE-ID: CWE-20 - Improper input validation

Exploit availability: No

Description

The vulnerability allows remote servers to perform a denial of service (DoS) attack.

The vulnerability exists due to insufficient validation of user-supplied input. A remote attacker can cause a denial of service (crash) via a crafted Edge Side Includes (ESI) response.

Mitigation

Update to version 3.5.18.

Vulnerable software versions

Squid: 2.3.devel2 - 3.5.17

External links

http://lists.opensuse.org/opensuse-security-announce/2016-08/msg00010.html
http://lists.opensuse.org/opensuse-security-announce/2016-08/msg00040.html
http://lists.opensuse.org/opensuse-updates/2016-08/msg00069.html
http://www.debian.org/security/2016/dsa-3625
http://www.openwall.com/lists/oss-security/2016/05/06/3
http://www.openwall.com/lists/oss-security/2016/05/06/5
http://www.oracle.com/technetwork/topics/security/linuxbulletinapr2016-2952096.html
http://www.securitytracker.com/id/1035770
http://www.squid-cache.org/Advisories/SQUID-2016_9.txt
http://www.squid-cache.org/Versions/v3/3.4/changesets/SQUID-2016_9.patch
http://www.squid-cache.org/Versions/v3/3.5/changesets/SQUID-2016_9.patch
http://www.ubuntu.com/usn/USN-2995-1
http://access.redhat.com/errata/RHSA-2016:1138
http://access.redhat.com/errata/RHSA-2016:1139
http://access.redhat.com/errata/RHSA-2016:1140
http://security.gentoo.org/glsa/201607-01

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.