client_side.cc in Squid before 3.5.18 and 4.x before 4.0.10 does not properly ignore the…
Priority HIGH 77CWE-345Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- None · High · None
- Fix status
- Fixed
Attack profile from CVSS 3.0 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-345.
Summary
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.
Why it matters now
EPSS 0.79969 99th percentileScored 2026-11-07
Fix Fixed Red Hat: 2 advisories
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
CPE configurations NVD · 15
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:canonical:ubuntu_linux:12.04:*:*:*:lts:*:*:* | 12.04 | Vulnerable | Canonical |
| cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:lts:*:*:* | 14.04 | Vulnerable | Canonical |
| cpe:2.3:o:canonical:ubuntu_linux:15.10:*:*:*:*:*:*:* | 15.10 | Vulnerable | Canonical |
| cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:* | 16.04 | Vulnerable | Canonical |
| cpe:2.3:a:squid-cache:squid:*:*:*:*:*:*:*:* | up to 3.5.17 | Vulnerable | squid-cache |
| cpe:2.3:a:squid-cache:squid:4.0.1:*:*:*:*:*:*:* | 4.0.1 | Vulnerable | squid-cache |
| cpe:2.3:a:squid-cache:squid:4.0.2:*:*:*:*:*:*:* | 4.0.2 | Vulnerable | squid-cache |
| cpe:2.3:a:squid-cache:squid:4.0.3:*:*:*:*:*:*:* | 4.0.3 | Vulnerable | squid-cache |
| cpe:2.3:a:squid-cache:squid:4.0.4:*:*:*:*:*:*:* | 4.0.4 | Vulnerable | squid-cache |
| cpe:2.3:a:squid-cache:squid:4.0.5:*:*:*:*:*:*:* | 4.0.5 | Vulnerable | squid-cache |
- cpe:2.3:o:canonical:ubuntu_linux:12.04:*:*:*:lts:*:*:* Versions 12.04 Vulnerable ·Canonical
- cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:lts:*:*:* Versions 14.04 Vulnerable ·Canonical
- cpe:2.3:o:canonical:ubuntu_linux:15.10:*:*:*:*:*:*:* Versions 15.10 Vulnerable ·Canonical
- cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:* Versions 16.04 Vulnerable ·Canonical
- cpe:2.3:a:squid-cache:squid:*:*:*:*:*:*:*:* Versions up to 3.5.17 Vulnerable ·squid-cache
- cpe:2.3:a:squid-cache:squid:4.0.1:*:*:*:*:*:*:* Versions 4.0.1 Vulnerable ·squid-cache
- cpe:2.3:a:squid-cache:squid:4.0.2:*:*:*:*:*:*:* Versions 4.0.2 Vulnerable ·squid-cache
- cpe:2.3:a:squid-cache:squid:4.0.3:*:*:*:*:*:*:* Versions 4.0.3 Vulnerable ·squid-cache
- cpe:2.3:a:squid-cache:squid:4.0.4:*:*:*:*:*:*:* Versions 4.0.4 Vulnerable ·squid-cache
- cpe:2.3:a:squid-cache:squid:4.0.5:*:*:*:*:*:*:* Versions 4.0.5 Vulnerable ·squid-cache
Show 5 more CPE
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:squid-cache:squid:4.0.6:*:*:*:*:*:*:* | 4.0.6 | Vulnerable | squid-cache |
| cpe:2.3:a:squid-cache:squid:4.0.7:*:*:*:*:*:*:* | 4.0.7 | Vulnerable | squid-cache |
| cpe:2.3:a:squid-cache:squid:4.0.8:*:*:*:*:*:*:* | 4.0.8 | Vulnerable | squid-cache |
| cpe:2.3:a:squid-cache:squid:4.0.9:*:*:*:*:*:*:* | 4.0.9 | Vulnerable | squid-cache |
| cpe:2.3:o:oracle:linux:7:*:*:*:*:*:*:* | 7 | Vulnerable | Oracle |
- cpe:2.3:a:squid-cache:squid:4.0.6:*:*:*:*:*:*:* Versions 4.0.6 Vulnerable ·squid-cache
- cpe:2.3:a:squid-cache:squid:4.0.7:*:*:*:*:*:*:* Versions 4.0.7 Vulnerable ·squid-cache
- cpe:2.3:a:squid-cache:squid:4.0.8:*:*:*:*:*:*:* Versions 4.0.8 Vulnerable ·squid-cache
- cpe:2.3:a:squid-cache:squid:4.0.9:*:*:*:*:*:*:* Versions 4.0.9 Vulnerable ·squid-cache
- cpe:2.3:o:oracle:linux:7:*:*:*:*:*:*:* Versions 7 Vulnerable ·Oracle
Remediation
Red Hat 2 advisories
- RHSA-2016:1140 Released 2016-05-31 · Red Hat rating Moderatesquid34 security update
- Red Hat Enterprise Linux Server (v. 6) squid34-7:3.4.14-9.el6_8.3
- Red Hat Enterprise Linux Workstation (v. 6) squid34-7:3.4.14-9.el6_8.3
- RHSA-2016:1139 Released 2016-05-31 · Red Hat rating Moderatesquid security update
- Red Hat Enterprise Linux Server (v. 7) squid-7:3.3.8-26.el7_2.3
- Red Hat Enterprise Linux Server Optional (v. 7) squid-sysvinit-7:3.3.8-26.el7_2.3
- Red Hat Enterprise Linux Workstation (v. 7) squid-7:3.3.8-26.el7_2.3
- Red Hat Enterprise Linux Workstation Optional (v. 7) squid-sysvinit-7:3.3.8-26.el7_2.3
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux Server (v. 6) | Fixed | RHSA-2016:1140 |
| Red Hat Enterprise Linux Server (v. 7) | Fixed | RHSA-2016:1139 |
| Red Hat Enterprise Linux Server Optional (v. 7) | Fixed | RHSA-2016:1139 |
| Red Hat Enterprise Linux Workstation (v. 6) | Fixed | RHSA-2016:1140 |
| Red Hat Enterprise Linux Workstation (v. 7) | Fixed | RHSA-2016:1139 |
| Red Hat Enterprise Linux Workstation Optional (v. 7) | Fixed | RHSA-2016:1139 |
Not affected: 2 products
- Red Hat Enterprise Linux 5
- Red Hat Enterprise Linux 6
Timeline
- 2026-10-02 Threatist record created from CVE-2016-4553
- 2026-10-03 Alias added: GHSA-p6vj-j24g-56wp
References
Advisory 11
- GLSA-201607-01
- http://www.oracle.com/technetwork/topics/security/linuxbulletinapr2016-2952096.html
- http://bugs.squid-cache.org/show_bug.cgi?id=4501
- SUSE-SU-2016:1996
- http://www.squid-cache.org/Advisories/SQUID-2016_7.txt
- USN-2995-1
- RHSA-2016:1140
- openSUSE-SU-2016:2081
- RHSA-2016:1139
- SUSE-SU-2016:2089
- DSA-3625
Sources
- CVE-2016-4553 · CVE Program
- CVE-2016-4553 · NVD
- FIRST EPSS
- GHSA-p6vj-j24g-56wp · GitHub Advisory Database · CC BY 4.0
- CVE-2016-4553 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences