CVE-2016-4554: Input Validation
Due to incorrect input validation Squid is vulnerable to a header smuggling attack leading to cache poisoning and to bypass of same-origin security policy in Squid and some client browsers.
External references:
http://www.squid-cache.org/Advisories/SQUID-20168.txt
Upstream fixes:
[RHEL-7]:
http://www.squid-cache.org/Versions/v3/3.3/changesets/SQUID-20168.patch>
[RHEL-6]:
http://www.squid-cache.org/Versions/v3/3.1/changesets/SQUID-20168.patch
[Fedora-22]:
http://www.squid-cache.org/Versions/v3/3.4/changesets/SQUID-20168.patch
[Fedora-23]:
http://www.squid-cache.org/Versions/v3/3.5/changesets/SQUID-20168.patch
Other sources
mimeheader.cc in Squid before 3.5.18 allows remote attackers to bypass intended same-origin restrictions and possibly conduct cache-poisoning attacks via a crafted HTTP Host header, aka a "header smuggling" issue.
— MITRE
Affected Software
Remediation
Event History
Frequently Asked Questions
What is the severity of CVE-2016-4554?
CVE-2016-4554 has a medium severity level due to its potential for abuse via header smuggling and cache poisoning.
How do I fix CVE-2016-4554?
To fix CVE-2016-4554, upgrade Squid to version 3.5.18 or later.
Which versions of Squid are affected by CVE-2016-4554?
CVE-2016-4554 affects Squid versions up to and including 3.5.17.
Can CVE-2016-4554 be exploited remotely?
Yes, CVE-2016-4554 can be exploited remotely by an attacker through a crafted HTTP Host header.
What kind of attack can CVE-2016-4554 allow?
CVE-2016-4554 can allow attackers to conduct cache poisoning attacks, compromising the integrity of the cache data.