CVE-2016-4052
CVE-2016-4052 is a high-severity vulnerability in Squid-cache Squid with a CVSS 3.x base score of 8.1. Its EPSS exploit-prediction score of 13% places it in the 96th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-119.
Key facts
- Severity: High (CVSS 3.x base score 8.1)
- CVSS v2: 6.8
- EPSS exploit prediction: 13% (96th percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-119
- Affected product: Squid-cache Squid
- Published:
- Last modified:
Description
Multiple stack-based buffer overflows in Squid 3.x before 3.5.17 and 4.x before 4.0.9 allow remote HTTP servers to cause a denial of service or execute arbitrary code via crafted Edge Side Includes (ESI) responses.
Frequently asked questions
- What is CVE-2016-4052?
- Multiple stack-based buffer overflows in Squid 3.x before 3.5.17 and 4.x before 4.0.9 allow remote HTTP servers to cause a denial of service or execute arbitrary code via crafted Edge Side Includes (ESI) responses.
- How severe is CVE-2016-4052?
- CVE-2016-4052 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
- Is CVE-2016-4052 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 13% (96th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2016-4052?
- CVE-2016-4052 primarily affects Squid-cache Squid. In total, 144 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
- How do I fix CVE-2016-4052?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- When was CVE-2016-4052 published?
- CVE-2016-4052 was published on 2016-04-25 and last updated on 2026-06-17.
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.openwall.com/lists/oss-security/2016/04/20/6
- http://www.openwall.com/lists/oss-security/2016/04/20/9
- http://www.oracle.com/technetwork/security-advisory/cpujul2016-2881720.html
- http://www.oracle.com/technetwork/topics/security/linuxbulletinapr2016-2952096.html
- http://www.securityfocus.com/bid/86788
- http://www.securityfocus.com/bid/91787
- http://www.securitytracker.com/id/1035647
- http://www.squid-cache.org/Advisories/SQUID-2016_6.txt
- http://www.ubuntu.com/usn/USN-2995-1
- https://access.redhat.com/errata/RHSA-2016:1138
- https://access.redhat.com/errata/RHSA-2016:1139
- https://access.redhat.com/errata/RHSA-2016:1140
- https://security.gentoo.org/glsa/201607-01
Affected products (144)
- cpe:2.3:o:canonical:ubuntu_linux:12.04:*:*:*:lts:*:*:*
- cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:lts:*:*:*
- cpe:2.3:o:canonical:ubuntu_linux:15.10:*:*:*:*:*:*:*
- cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:*
- cpe:2.3:a:squid-cache:squid:3.0:*:*:*:*:*:*:*
- cpe:2.3:a:squid-cache:squid:3.1:*:*:*:*:*:*:*
- cpe:2.3:a:squid-cache:squid:3.1.0.1:*:*:*:*:*:*:*
- cpe:2.3:a:squid-cache:squid:3.1.0.2:*:*:*:*:*:*:*
- cpe:2.3:a:squid-cache:squid:3.1.0.3:*:*:*:*:*:*:*
- cpe:2.3:a:squid-cache:squid:3.1.0.4:*:*:*:*:*:*:*
- cpe:2.3:a:squid-cache:squid:3.1.0.5:*:*:*:*:*:*:*
- cpe:2.3:a:squid-cache:squid:3.1.0.6:*:*:*:*:*:*:*
- cpe:2.3:a:squid-cache:squid:3.1.0.7:*:*:*:*:*:*:*
- cpe:2.3:a:squid-cache:squid:3.1.0.8:*:*:*:*:*:*:*
- cpe:2.3:a:squid-cache:squid:3.1.0.9:*:*:*:*:*:*:*
- cpe:2.3:a:squid-cache:squid:3.1.0.10:*:*:*:*:*:*:*
- cpe:2.3:a:squid-cache:squid:3.1.0.11:*:*:*:*:*:*:*
- cpe:2.3:a:squid-cache:squid:3.1.0.12:*:*:*:*:*:*:*
- cpe:2.3:a:squid-cache:squid:3.1.0.13:*:*:*:*:*:*:*
- cpe:2.3:a:squid-cache:squid:3.1.0.14:*:*:*:*:*:*:*
- cpe:2.3:a:squid-cache:squid:3.1.0.15:*:*:*:*:*:*:*
- cpe:2.3:a:squid-cache:squid:3.1.0.16:*:*:*:*:*:*:*
- cpe:2.3:a:squid-cache:squid:3.1.0.17:*:*:*:*:*:*:*
- cpe:2.3:a:squid-cache:squid:3.1.0.18:*:*:*:*:*:*:*
- cpe:2.3:a:squid-cache:squid:3.1.1:*:*:*:*:*:*:*
- cpe:2.3:a:squid-cache:squid:3.1.2:*:*:*:*:*:*:*
- cpe:2.3:a:squid-cache:squid:3.1.3:*:*:*:*:*:*:*
- cpe:2.3:a:squid-cache:squid:3.1.4:*:*:*:*:*:*:*
- cpe:2.3:a:squid-cache:squid:3.1.5:*:*:*:*:*:*:*
- cpe:2.3:a:squid-cache:squid:3.1.5.1:*:*:*:*:*:*:*
- cpe:2.3:a:squid-cache:squid:3.1.6:*:*:*:*:*:*:*
- cpe:2.3:a:squid-cache:squid:3.1.7:*:*:*:*:*:*:*
- cpe:2.3:a:squid-cache:squid:3.1.8:*:*:*:*:*:*:*
- cpe:2.3:a:squid-cache:squid:3.1.9:*:*:*:*:*:*:*
- cpe:2.3:a:squid-cache:squid:3.1.10:*:*:*:*:*:*:*
- cpe:2.3:a:squid-cache:squid:3.1.11:*:*:*:*:*:*:*
- cpe:2.3:a:squid-cache:squid:3.1.12:*:*:*:*:*:*:*
- cpe:2.3:a:squid-cache:squid:3.1.12.1:*:*:*:*:*:*:*
- cpe:2.3:a:squid-cache:squid:3.1.12.2:*:*:*:*:*:*:*
- cpe:2.3:a:squid-cache:squid:3.1.12.3:*:*:*:*:*:*:*
More vulnerabilities in Squid-cache Squid
- CVE-2025-62168 — Critical (CVSS 10.0): Squid is a caching proxy for the Web. In Squid versions prior to 7.2, a failure to redact HTTP authentication…
- CVE-2020-15049 — Critical (CVSS 9.9): An issue was discovered in http/ContentLengthInterpreter.cc in Squid before 4.12 and 5.x before 5.0.3. A Request…
- CVE-2020-11945 — Critical (CVSS 9.8): An issue was discovered in Squid before 5.0.2. A remote attacker can replay a sniffed Digest Authentication nonce to…
- CVE-2019-12519 — Critical (CVSS 9.8): An issue was discovered in Squid through 4.7. When handling the tag esi:when when ESI is enabled, Squid calls…
- CVE-2019-12524 — Critical (CVSS 9.8): An issue was discovered in Squid through 4.7. When handling requests from users, Squid checks its rules to see if the…
- CVE-2019-12526 — Critical (CVSS 9.8): An issue was discovered in Squid before 4.9. URN response handling in Squid suffers from a heap-based buffer overflow.…
All CVEs affecting Squid-cache Squid →
Other CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer) vulnerabilities
- CVE-2026-2778 — Critical (CVSS 10.0): Sandbox escape due to incorrect boundary conditions in the DOM: Core & HTML component. This vulnerability was fixed in…
- CVE-2026-2776 — Critical (CVSS 10.0): Sandbox escape due to incorrect boundary conditions in the Telemetry component in External Software. This vulnerability…
- CVE-2025-1866 — Critical (CVSS 10.0): Improper Restriction of Operations within the Bounds of a Memory Buffer vulnerability in warmcat libwebsockets allows…
- CVE-2022-27625 — Critical (CVSS 10.0): A vulnerability regarding improper restriction of operations within the bounds of a memory buffer is found in the…
- CVE-2022-27624 — Critical (CVSS 10.0): A vulnerability regarding improper restriction of operations within the bounds of a memory buffer is found in the…
- CVE-2020-11896 — Critical (CVSS 10.0): The Treck TCP/IP stack before 6.0.1.66 allows Remote Code Execution, related to IPv4 tunneling.
Threat intelligence
Threat-intel indicators referencing this CVE:
- 193.90.12.40 (ipv4-addr)
- 200.89.159.59 (ipv4-addr)