CVE-2016-4554

Severity: high (CVSS 8.6 v3.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 38.9% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2016-05-10 · updated 2026-06-17
Weakness: CWE-345

Description

mime_header.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.

Affected products

Canonical Ubuntu Linux: 12.04, 14.04, 15.10, 16.04
Oracle Corporation Oracle Linux: 6, 7
Squid: through 3.5.17

References

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.oracle.com/technetwork/topics/security/linuxbulletinapr2016-2952096.html
http://www.securitytracker.com/id/1035769
http://www.squid-cache.org/Advisories/SQUID-2016_8.txt
http://www.squid-cache.org/Versions/v3/3.1/changesets/SQUID-2016_8.patch
http://www.squid-cache.org/Versions/v3/3.2/changesets/SQUID-2016_8.patch
http://www.squid-cache.org/Versions/v3/3.3/changesets/SQUID-2016_8.patch
http://www.squid-cache.org/Versions/v3/3.4/changesets/SQUID-2016_8.patch
http://www.squid-cache.org/Versions/v3/3.5/changesets/SQUID-2016_8.patch

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