CVE-2016-4556: Double Free
Double free vulnerability in Esi.cc in Squid 3.x before 3.5.18 and 4.x before 4.0.10 allows remote servers to cause a denial of service (crash) via a crafted Edge Side Includes (ESI) response.
Other sources
Due to incorrect reference counting Squid is vulnerable to a denial of service attack when processing ESI responses.
External references:
http://www.squid-cache.org/Advisories/SQUID-20169.txt
Upstream fixes:
Squid 3.5:
http://www.squid-cache.org/Versions/v3/3.5/changesets/SQUID-20169.patch
Squid 3.4:
http://www.squid-cache.org/Versions/v3/3.4/changesets/SQUID-20169.patch
NOTE: For the other related CVE, CVE-2016-4555, see Bug 1334246
— Red Hat
Affected Software
Remediation
Event History
Frequently Asked Questions
What is the severity of CVE-2016-4556?
CVE-2016-4556 has a severity rating that allows remote servers to cause a denial of service through crafted ESI responses.
How do I fix CVE-2016-4556?
To fix CVE-2016-4556, update Squid to version 3.5.18 or newer, or 4.0.10 or newer.
What versions are affected by CVE-2016-4556?
CVE-2016-4556 affects Squid versions prior to 3.5.18 and 4.0.10.
What type of vulnerability is CVE-2016-4556?
CVE-2016-4556 is a double free vulnerability that can lead to denial of service.
Who can exploit CVE-2016-4556?
CVE-2016-4556 can be exploited by remote attackers via specially crafted ESI responses.