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Vulnerability record · CVE-2020-25097 · published 19 March 2021

CVE-2020-25097: Squid-cache squid improper input validation vulnerability

Squid Cache · Squid

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.

8.6 CVSS 3.1 High EPSS 8.2% · top 5.3% CWE-20 · Improper input validationCWE-444 · HTTP request smuggling
8.6CVSS 3.1 base score, v2 5.0
8.2%EPSS exploitation probability, 30 days
NoNot in CISA KEV
4Affected product versions listed by NVD
18References
17 Jun 2026Last modified by 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.

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

Affected products

4 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
http://www.squid-cache.org/Versions/v4/changesets/SQUID-2020_11.patch Mailing ListPatchVendor Advisory
http://www.squid-cache.org/Versions/v5/changesets/SQUID-2020_11.patch Mailing ListPatchVendor Advisory
https://github.com/squid-cache/squid/security/advisories/GHSA-jvf6-h9gj-pmj6 PatchThird Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/DJMDRVV677AJL4BZAOLCT5L
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FBXFWKIGXPERDVQXG556LLP
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/O3RYBDMJCPYGOSURWDR3WJT
https://security.gentoo.org/glsa/202105-14 Third Party Advisory
https://security.netapp.com/advisory/ntap-20210727-0010/ Third Party Advisory
https://www.debian.org/security/2021/dsa-4873 Third Party Advisory
http://www.squid-cache.org/Versions/v4/changesets/SQUID-2020_11.patch Mailing ListPatchVendor Advisory
http://www.squid-cache.org/Versions/v5/changesets/SQUID-2020_11.patch Mailing ListPatchVendor Advisory
https://github.com/squid-cache/squid/security/advisories/GHSA-jvf6-h9gj-pmj6 PatchThird Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/DJMDRVV677AJL4BZAOLCT5L
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FBXFWKIGXPERDVQXG556LLP
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/O3RYBDMJCPYGOSURWDR3WJT
https://security.gentoo.org/glsa/202105-14 Third Party Advisory
https://security.netapp.com/advisory/ntap-20210727-0010/ Third Party Advisory
https://www.debian.org/security/2021/dsa-4873 Third Party Advisory

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Source: NIST National Vulnerability Database (record CVE-2020-25097), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.