The "%xx" URL decoding function in Squid 2.5STABLE4 and earlier allows remote attackers…
Priority MEDIUM 48Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- — Not recorded in CVSS 2.0
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- Partial · Partial · Partial
- Fix status
- Fixed
Attack profile from CVSS 2.0 · NVD. Fix status from CNA and Red Hat.
Summary
The "%xx" URL decoding function in Squid 2.5STABLE4 and earlier allows remote attackers to bypass url_regex ACLs via a URL with a NULL ("%00") character, which causes Squid to use only a portion of the requested URL when comparing it against the access control lists.
Why it matters now
EPSS 0.13807 96th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed Red Hat: 2 advisories
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
CPE configurations NVD · 7
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:squid:squid:2.0_patch2:*:*:*:*:*:*:* | 2.0_patch2 | Vulnerable | Squid |
| cpe:2.3:a:squid:squid:2.1_patch2:*:*:*:*:*:*:* | 2.1_patch2 | Vulnerable | Squid |
| cpe:2.3:a:squid:squid:2.3_stable5:*:*:*:*:*:*:* | 2.3_stable5 | Vulnerable | Squid |
| cpe:2.3:a:squid:squid:2.4:*:*:*:*:*:*:* | 2.4 | Vulnerable | Squid |
| cpe:2.3:a:squid:squid:2.4_stable7:*:*:*:*:*:*:* | 2.4_stable7 | Vulnerable | Squid |
| cpe:2.3:a:squid:squid:2.5_stable3:*:*:*:*:*:*:* | 2.5_stable3 | Vulnerable | Squid |
| cpe:2.3:a:squid:squid:2.5_stable4:*:*:*:*:*:*:* | 2.5_stable4 | Vulnerable | Squid |
- cpe:2.3:a:squid:squid:2.0_patch2:*:*:*:*:*:*:* Versions 2.0_patch2 Vulnerable ·Squid
- cpe:2.3:a:squid:squid:2.1_patch2:*:*:*:*:*:*:* Versions 2.1_patch2 Vulnerable ·Squid
- cpe:2.3:a:squid:squid:2.3_stable5:*:*:*:*:*:*:* Versions 2.3_stable5 Vulnerable ·Squid
- cpe:2.3:a:squid:squid:2.4:*:*:*:*:*:*:* Versions 2.4 Vulnerable ·Squid
- cpe:2.3:a:squid:squid:2.4_stable7:*:*:*:*:*:*:* Versions 2.4_stable7 Vulnerable ·Squid
- cpe:2.3:a:squid:squid:2.5_stable3:*:*:*:*:*:*:* Versions 2.5_stable3 Vulnerable ·Squid
- cpe:2.3:a:squid:squid:2.5_stable4:*:*:*:*:*:*:* Versions 2.5_stable4 Vulnerable ·Squid
Remediation
Red Hat 2 advisories
- RHSA-2004:133 Released 2004-04-14 · Red Hat rating Lowsquid security update
- Red Hat Desktop version 3 squid-7:2.5.STABLE3-5.3E, squid-7:2.5.STABLE3-5.3E.i386
- Red Hat Enterprise Linux AS version 3 squid-7:2.5.STABLE3-5.3E, squid-7:2.5.STABLE3-5.3E.i386, squid-7:2.5.STABLE3-5.3E.ia64 +1
- Red Hat Enterprise Linux ES version 3 squid-7:2.5.STABLE3-5.3E, squid-7:2.5.STABLE3-5.3E.i386, squid-7:2.5.STABLE3-5.3E.ia64
- Red Hat Enterprise Linux WS version 3 squid-7:2.5.STABLE3-5.3E, squid-7:2.5.STABLE3-5.3E.i386, squid-7:2.5.STABLE3-5.3E.ia64
- RHSA-2004:134 Released 2004-03-29 · Red Hat rating Low: Updated squid package fixes security vulnerability
- Red Hat Linux 9
Vendor assessments
Red Hat
Red Hat rating: Low. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Desktop version 3 | Fixed | RHSA-2004:133 |
| Red Hat Enterprise Linux AS version 3 | Fixed | RHSA-2004:133 |
| Red Hat Enterprise Linux ES version 3 | Fixed | RHSA-2004:133 |
| Red Hat Enterprise Linux WS version 3 | Fixed | RHSA-2004:133 |
| Red Hat Linux 9 | Fixed | RHSA-2004:134 |
Timeline
- 2026-10-02 Threatist record created from CVE-2004-0189
- 2026-10-03 Alias added: GHSA-wgp5-p97p-cph9
References
More Squid vulnerabilities
- TI-2009-00458 Squid 2.7 to 2.7.STABLE5, 3.0 to 3.0.STABLE12, and 3.1 to 3.1.0.4 allows remote attackers… CVSS 2.0MEDIUM 5.0
- TI-2005-00207 The httpProcessReplyHeader function in http.c for Squid 2.5-STABLE7 and earlier does not… CVSS 2.0MEDIUM 5.0
- TI-2005-00080 The WCCP message parsing code in Squid 2.5.STABLE7 and earlier allows remote attackers to… CVSS 2.0MEDIUM 5.0
- TI-2005-00142 squid_ldap_auth in Squid 2.5 and earlier allows remote authenticated users to bypass… CVSS 2.0HIGH 7.5
- TI-2005-00143 Squid 2.5 up to 2.5.STABLE7 allows remote attackers to poison the cache or conduct… CVSS 2.0MEDIUM 5.0
- TI-2005-00404 Squid 2.5.STABLE8 and earlier allows remote attackers to cause a denial of service… CVSS 2.0MEDIUM 5.0
Sources
- CVE-2004-0189 · CVE Program
- CVE-2004-0189 · NVD
- FIRST EPSS
- GHSA-wgp5-p97p-cph9 · GitHub Advisory Database · CC BY 4.0
- CVE-2004-0189 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences