CVE intelligence and bounded remediation

CVE-2020-25097 — An issue was discovered in Squid through 4.13 and 5.x through 5.0.4

High CVSS 8.6

An issue was discovered in Squid through 4.13 and 5.x through 5.0.4. Due to improper input validation, it allows a trusted client to perform HTTP Request Smuggling and access services otherwise forbidden by the security controls. This occurs for certain uri_whitespace configuration settings.

Severity
High
CVSS
8.6 (3.1)
Published
2021-03-19
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-20, CWE-444

Affected products

  • squid-cache / squid
  • debian / debian_linux / 10.0
  • fedoraproject / fedora / 32
  • fedoraproject / fedora / 33
  • fedoraproject / fedora / 34
  • netapp / cloud_manager

Showing 6 representative product identities from 7 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

HTTP request smuggling and message-boundary ambiguity

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Inventory every proxy, CDN, gateway, load balancer, service mesh, and application server hop on affected request paths.
  • Compare documented parsing and normalization behavior for message length, transfer coding, duplicate headers, and protocol translation.
  • Identify connection reuse and which downstream services trust headers added by intermediaries.

Remediate safely

  • Update affected intermediaries and origin servers and align them on a single standards-compliant request framing policy.
  • Reject ambiguous length, transfer-coding, duplicate, malformed, and unsupported framing before forwarding.
  • Normalize or remove hop-by-hop and identity headers at one controlled boundary and add multi-hop regression tests.

Authoritative sources

Complete CVE record and remediation plan

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