Cyber Resilience

CVE-2016-4054

Memory Safety in Squid-Cache Squid 3.0 … 4.0.8

High EPSSMemory Safety
Published
25 April 2016
Modified
06 May 2026
Patch / advisory
CVSS Score v3 8.1
Click a component to see what it means
Raw vectorCVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.78 99.5th percentile
Risk Priority 81 floored blend · peak EPSS

Summary

CVE-2016-4054 is a high-severity Improper Restriction of Operations within the Bounds of a Memory Buffer (CWE-119) vulnerability in Squid-Cache Squid. Its CVSS base score is 8.1 (High).

Operationally, ranked in the top 0.5% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability Data

Buffer overflow in Squid 3.x before 3.5.17 and 4.x before 4.0.9 allows remote attackers to execute arbitrary code via crafted Edge Side Includes (ESI) responses.

CWE(s)

Related Threats

Likely ATT&CK TechniquesAI

Techniques this vulnerability likely enables, inferred from its description, weakness type, and attributed-actor tradecraft. Confidence is per-technique.

T1190 Exploit Public-Facing Application Initial Accessconfidence: HIGH
Remote attackers can exploit the buffer overflow in Squid's ESI processing to execute arbitrary code on a public-facing proxy server.
T1203 Exploitation for Client Execution Executionconfidence: HIGH
Successful exploitation of the ESI buffer overflow results in code execution on the client (Squid proxy) without user interaction.
inferred from description + CWE · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2016-4553Same product: Canonical Ubuntu Linux
CVE-2018-7584Same product: Canonical Ubuntu Linux
CVE-2018-4233Same product: Canonical Ubuntu Linux
CVE-2017-14492Same product: Canonical Ubuntu Linux
CVE-2017-14493Same product: Canonical Ubuntu Linux
CVE-2015-7547Same product: Canonical Ubuntu Linux
CVE-2013-1690Same product: Canonical Ubuntu Linux
CVE-2023-30431Same vendor: Oracle
CVE-2026-21991Same product: Oracle Linux
CVE-2026-33515Same product: Squid-Cache Squid

Affected Assets

canonical
ubuntu linux
12.04, 14.04, 15.10, 16.04
squid-cache
squid
3.0, 3.1, 3.1.0.1, 3.1.0.10, 3.1.0.11
oracle
linux
6, 7

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V17.3.2

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-119

Ongoing control assessments and code testing (static/dynamic analysis, fuzzing) surface memory buffer restriction failures, which are then remediated before release.

addresses: CWE-119

Managed runtimes used by platform-independent applications (e.g., JVM, CLR) enforce memory safety, preventing most buffer overflows that require direct memory manipulation.

addresses: CWE-119

Memory protections (e.g., W^X, ASLR) make exploitation of buffer-boundary violations far harder to turn into code execution.

addresses: CWE-119

Detects exploitation attempts that produce memory corruption, crashes, or anomalous behavior.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices (bounds checking, safe APIs, reviews) directly prevent this class of flaw.

ID.RA-01 partial match
prevents

Vulnerability scanning and code analysis directly surface buffer-boundary flaws.

ID.RA-08 partial match
prevents

Receiving and triaging vulnerability disclosures commonly includes buffer-related reports.

PR.AT-02 partial match
prevents

Developer training on secure coding reduces introduction of memory-buffer errors.

PR.PS-02 partial match
prevents

Patching replaces vulnerable code containing buffer-boundary defects.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

detects

Security testing in development catches out-of-bounds accesses before release, covering most instances of the weakness.

prevents

Secure development lifecycle mandates memory-safety practices that directly prevent buffer-boundary violations.

prevents

Application security requirements can specify memory-safety rules, but do not prescribe implementation details.

prevents

Secure architecture and engineering principles include memory-safe design patterns that mitigate buffer overflows.

prevents

Secure coding standards explicitly forbid unsafe buffer operations, directly eliminating CWE-119.

References