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No exploitation reportedFix available

CVE-2016-4553

No exploitation reported by the sources we read.

  • Published2016-05-10
  • WeaknessCWE-345

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

client_side.cc in Squid before 3.5.18 and 4.x before 4.0.10 does not properly ignore the Host header when absolute-URI is provided, which allows remote attackers to conduct cache-poisoning attacks via an HTTP request.

Timeline

dates in UTC
  1. 2016-05-1019:59CVE publishedNVD
  2. 2026-10-2319:23EPSS crossed 10 %FIRST EPSS

Versions per branch

NVD
Squid-cache squid
BranchAffectedFixed in
3.5≤ 3.5.17no fix published
4.0= 4.0.1no fix published
4.0= 4.0.2no fix published
4.0= 4.0.3no fix published
4.0= 4.0.4no fix published
4.0= 4.0.5no fix published
4.0= 4.0.6no fix published
4.0= 4.0.7no fix published
4.0= 4.0.8no fix published
4.0= 4.0.9no fix published
Canonical ubuntu linux
BranchAffectedFixed in
12.4= 12.04no fix published
14.4= 14.04no fix published
15.10= 15.10no fix published
16.4= 16.04no fix published
Oracle linux
BranchAffectedFixed in
7.x= 7no fix published

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

  • squidSUSE:Linux Enterprise Server for SAP Applications 12 SP1all versions · fixed in 3.3.14-20.2
  • squidSUSE:Linux Enterprise Server 12 SP1all versions · fixed in 3.3.14-20.2
  • squidRed Hat:enterprise_linux:7::workstationall versions · fixed in 7:3.3.8-26.el7_2.3and 2 other packages
  • squidRed Hat:enterprise_linux:7::serverall versions · fixed in 7:3.3.8-26.el7_2.3and 2 other packages
  • squidopenSUSE:Tumbleweedall versions · fixed in 4.16-1.5
  • squidMageia:5all versions · fixed in 3.5.19-1.mga5
  • squid3Ubuntu:16.04:LTSall versions · fixed in 3.5.12-1ubuntu7.2
  • squid3Ubuntu:14.04:LTSall versions · fixed in 3.3.8-1ubuntu6.8

5 more package ranges on OSV.dev

Vendor advisories

  • CVE-2016-4553 Red Hat Product Security36 products fixed

    squid: Cache poisoning issue in HTTP Request handling

  • RHSA-2016:1140 Red Hat Product Security14 products fixed

    Red Hat Security Advisory: squid34 security update

  • RHSA-2016:1139 Red Hat Product Security22 products fixed

    Red Hat Security Advisory: squid security update

Full record on NVD

Fix

  1. Vendor fix Red Hat Product Security RHSA-2016:1140 · 14 productsFor details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 After installing this update, the squid service will be restarted automatically.

Advisories and patches

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof of concept
Metasploit modules
none listed
Metasploit Framework

Sources

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N
Published
2016-05-10
Last Modified
2026-06-17
NVD status
Modified
GitHub Advisory
GHSA-p6vj-j24g-56wp

Frequently asked questions

What is CVE-2016-4553?

client_side.cc in Squid before 3.5.18 and 4.x before 4.0.10 does not properly ignore the Host header when absolute-URI is provided, which allows remote attackers to conduct cache-poisoning attacks via an HTTP request.

Is CVE-2016-4553 actively exploited?

Active exploitation of CVE-2016-4553 has not been confirmed. Its EPSS score was 80.0% on 2026-11-09, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2016-4553?

CVE-2016-4553 has a CVSS v3 base score of 8.6 (HIGH severity), with vector string CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N.

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Related vulnerabilities

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Sources for this record