CVE-2016-4553
Squid-Cache Squid ≤ 3.5.17
Raw vector
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:NSummary
CVE-2016-4553 is a high-severity Insufficient Verification of Data Authenticity (CWE-345) vulnerability in Squid-Cache Squid. Its CVSS base score is 8.6 (High).
Operationally, ranked in the top 0.4% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2016-5540
Vulnerability Data
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.
- 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.
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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- 8 hardening rules · 5 OS baselines
V3.5.5
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.
Directly requires independent verification of matching output before adverse decisions, mitigating insufficient authenticity checks on data from external sources.
Use of approved PKI certificates provides verifiable data authenticity and origin for communications and artifacts.
Mandates provision of authenticity and integrity artifacts that enable verification of name/address resolution data.
Requires explicit verification of data authenticity from authoritative sources, preventing acceptance of unauthenticated resolution responses.
Control requires verification of data authenticity/integrity (e.g., checksums) after aggregation/packing, directly reducing exploitation of insufficient verification before transmission.
Time synchronization supports reliable freshness verification when checking data authenticity across systems or components.
Mandates verification of data authenticity for software, firmware, and information.
Provenance documentation and monitoring directly enables verification of authenticity for components and data throughout their history.
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.
CWE-345 directly impairs RC.RP-05's verification of restored-asset integrity/authenticity, largely defeating the outcome while still leaving other restoration-confirmation steps partially viable.
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.
Security testing can detect missing or weak data authenticity verification.
Network controls can enforce authenticated channels, reducing risk of accepting unauthentic data.
Secure network services often include authenticity checks for data exchanged over those services.
Cryptographic mechanisms directly verify data origin and integrity, preventing acceptance of unauthentic data.
Secure SDLC incorporates authenticity verification requirements throughout development.
Application security requirements can mandate data authenticity verification mechanisms.