CVE-2020-25097

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.

Published: 2021-03-19 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2020-25097 is rated High Risk (72.3/100): CVSS High severity, with high exploitation likelihood (EPSS 8.16%, 94th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. EPSS rose +7.58% over the last day, indicating growing attacker interest. High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2020-25097

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.58% 8.16% +7.58%
2 2025-12-28 1.80% 0.58% -1.22%
3 2025-12-27 — 1.80% —

Full EPSS history (25 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-25097

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.6 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 4.0 [email protected]
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:P/I:N/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:N)
No availability impact.
 10.0 2.9 [email protected]

Weakness enumeration for CVE-2020-25097

OS Trackers for CVE-2020-25097

vendor priority summary link
alpine high CVE-2020-25097: 1 source package rows (squid); 40 state rows across 10 repos (3.10-main, 3.11-main, 3.12-main, 3.17-main, 3.18-main, 3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-main); fixed 10, open 30. https://security.alpinelinux.org/vuln/CVE-2020-25097
debian not yet assigned CVE-2020-25097 not yet assigned priority: Debian including 1 source packages (squid), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2020-25097
gentoo normal CVE-2020-25097: 1 GLSA(s) (202105-14), 1 atom(s) (net-proxy/squid); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2020-25097
redhat high — https://access.redhat.com/security/cve/CVE-2020-25097
suse high — https://www.suse.com/security/cve/CVE-2020-25097/
ubuntu medium CVE-2020-25097 medium priority: Ubuntu including 2 source packages (squid, squid3), 14 status rows across 7 suites (bionic, focal, groovy, hirsute, trusty, upstream, xenial): DNE 7, released 6, needed 1. https://ubuntu.com/security/CVE-2020-25097

Affected software / configurations for CVE-2020-25097

Vendor Product Version Raw CPE
squid-cache squid >= 2.0, < 4.14 cpe:2.3:a:squid-cache:squid:*:*:*:*:*:*:*:*
squid-cache squid >= 5.0.1, < 5.0.5 cpe:2.3:a:squid-cache:squid:*:*:*:*:*:*:*:*
debian debian_linux 10.0 cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
fedoraproject fedora 32 cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*
fedoraproject fedora 33 cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*
fedoraproject fedora 34 cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*
netapp cloud_manager — cpe:2.3:a:netapp:cloud_manager:-:*:*:*:*:*:*:*

References for CVE-2020-25097

URL Tags
http://www.squid-cache.org/Versions/v4/changesets/SQUID-2020_11.patch Mailing List Patch Vendor Advisory
http://www.squid-cache.org/Versions/v5/changesets/SQUID-2020_11.patch Mailing List Patch Vendor Advisory
https://github.com/squid-cache/squid/security/advisories/GHSA-jvf6-h9gj-pmj6 Patch Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/DJMDRVV677AJL4BZAOLCT5LMFCGBZTC2/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FBXFWKIGXPERDVQXG556LLPUOCMQGERC/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/O3RYBDMJCPYGOSURWDR3WJTE474UFT77/
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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