CVE & CISA-KEV Catalog

CVE-2020-25097

HIGHEPSS 95th pctl
8.6
CVSS v3
NVD

Description

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.

How to fix

Remediation Available
squidAmazon
Fixed in:7:3.5.20-17.amzn2.6.1
Fixed in:7:3.5.20-17.amzn2.6.1
Fixed in:7:3.5.20-17.amzn2.6.1
squid-debuginfoAmazon
Fixed in:7:3.5.20-17.amzn2.6.1
Fixed in:7:3.5.20-17.amzn2.6.1
Fixed in:7:3.5.20-17.amzn2.6.1
squid-migration-scriptAmazon
Fixed in:7:3.5.20-17.amzn2.6.1
Fixed in:7:3.5.20-17.amzn2.6.1
Fixed in:7:3.5.20-17.amzn2.6.1
squid-sysvinitAmazon
Fixed in:7:3.5.20-17.amzn2.6.1
Fixed in:7:3.5.20-17.amzn2.6.1
Fixed in:7:3.5.20-17.amzn2.6.1
squidDebian
Fixed in:4.13-8CVE-2020-25097
Fixed in:4.13-8CVE-2020-25097
Fixed in:4.13-8CVE-2020-25097
squidUbuntu
Fixed in:3.5.12-1ubuntu7.16USN-4895-1

This Ubuntu release reached end-of-life on 2021-04-02.

Fixed in:3.5.27-1ubuntu1.10USN-4895-1

This Ubuntu release reached end-of-life on 2023-05-31. Extended security maintenance is available until 2028-04-01.

Fixed in:4.10-1ubuntu1.3USN-4895-1

This Ubuntu release reached end-of-life on 2025-05-31. Extended security maintenance is available until 2030-04-02.

squid3Ubuntu
Fixed in:3.5.12-1ubuntu7.16USN-4895-1

This Ubuntu release reached end-of-life on 2021-04-02.

Fixed in:3.5.27-1ubuntu1.10USN-4895-1

This Ubuntu release reached end-of-life on 2023-05-31. Extended security maintenance is available until 2028-04-01.

TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredNone
User InteractionNone
ScopeChanged

Impact

ConfidentialityHigh
IntegrityNone
AvailabilityNone

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N

Exploit Intelligence

8.16%probability of exploitation in 30 days
95thpercentile

High risk: more likely to be exploited than 95% of all known CVEs.

References

Related Vulnerabilities

Other CWE-20 (Improper Input Validation) vulnerabilities, ordered by exploit likelihood. View all

CVESeverityCVSSEPSSExploitedFix
CVE-2024-3400Critical10.0100%KEV + Ransom-
CVE-2021-45105Medium5.9100%-Fix
CVE-2021-44228Critical10.0100%KEV + RansomFix
CVE-2021-21985Critical9.8100%KEV + RansomFix
CVE-2020-3452High7.5100%KEVFix
CVE-2018-7600Critical9.8100%KEV + RansomFix

Common questions

How do I fix CVE-2020-25097?

Published advisories record a fix for 7 affected products. The "How to fix" section on this page lists the fixed version and source advisory for each one, so apply the entry matching what you actually run.

Is CVE-2020-25097 being actively exploited?

Not that we know of. CVE-2020-25097 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 8.2% is the estimated probability that it will be exploited in the next 30 days. That is higher than 95% of all scored CVEs.

How severe is CVE-2020-25097?

CVE-2020-25097 has a CVSS v3 base score of 8.6, rated high. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.

What does CVE-2020-25097 affect?

Published advisories record a fix for squid (Amazon), squid-debuginfo (Amazon), squid-migration-script (Amazon), squid-sysvinit (Amazon), and 3 more. Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-06-17.