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Vulnerability record · CVE-2004-0189 · published 15 March 2004

CVE-2004-0189: Squid vulnerability

Squid · Squid

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.

7.5 CVSS 2.0 High EPSS 14% · top 3.6%
7.5CVSS 2.0 base score
14%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
30References, 4 tagged exploit
16 Jun 2026Last modified by NVD

Description

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.

AV:N/AC:L/Au:N/C:P/I:P/A:P

Affected products

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

References

LinkTags
ftp://ftp.sco.com/pub/updates/UnixWare/SCOSA-2005.16/SCOSA-2005.16.txt
ftp://patches.sgi.com/support/free/security/advisories/20040404-01-U.asc
http://distro.conectiva.com.br/atualizacoes/?id=a&anuncio=000838
http://marc.info/?l=bugtraq&m=108084935904110&w=2
http://security.gentoo.org/glsa/glsa-200403-11.xml
http://www.debian.org/security/2004/dsa-474
http://www.mandrakesoft.com/security/advisories?name=MDKSA-2004:025
http://www.osvdb.org/5916
http://www.redhat.com/support/errata/RHSA-2004-133.html
http://www.redhat.com/support/errata/RHSA-2004-134.html
http://www.securityfocus.com/bid/9778 ExploitPatchVendor Advisory
http://www.squid-cache.org/Advisories/SQUID-2004_1.txt ExploitPatchVendor Advisory
https://exchange.xforce.ibmcloud.com/vulnerabilities/15366
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A877
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A941
ftp://ftp.sco.com/pub/updates/UnixWare/SCOSA-2005.16/SCOSA-2005.16.txt
ftp://patches.sgi.com/support/free/security/advisories/20040404-01-U.asc
http://distro.conectiva.com.br/atualizacoes/?id=a&anuncio=000838
http://marc.info/?l=bugtraq&m=108084935904110&w=2
http://security.gentoo.org/glsa/glsa-200403-11.xml
http://www.debian.org/security/2004/dsa-474
http://www.mandrakesoft.com/security/advisories?name=MDKSA-2004:025
http://www.osvdb.org/5916
http://www.redhat.com/support/errata/RHSA-2004-133.html
http://www.redhat.com/support/errata/RHSA-2004-134.html
http://www.securityfocus.com/bid/9778 ExploitPatchVendor Advisory
http://www.squid-cache.org/Advisories/SQUID-2004_1.txt ExploitPatchVendor Advisory
https://exchange.xforce.ibmcloud.com/vulnerabilities/15366
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A877
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A941

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

10.0CVE-2005-0194Squid vulnerabilitySquid 2.5, when processing the configuration file, parses empty Access Control Lists (ACLs), including proxy_auth ACLs without defined auth schemes, …EPSS 5.1%7.5CVE-2005-1711Clam anti-virus clamav vulnerabilityGibraltar Firewall 2.2 and earlier, when using the ClamAV update to 0.81 for Squid, uses a defunct ClamAV method to scan memory for viruses, which do…EPSS 1.0%7.5CVE-2005-0173Squid vulnerabilitysquid_ldap_auth in Squid 2.5 and earlier allows remote authenticated users to bypass username-based Access Control Lists (ACLs) via a username with a…EPSS 32%7.5CVE-2005-1345Squid vulnerabilitySquid 2.5.STABLE9 and earlier does not trigger a fatal error when it identifies missing or invalid ACLs in the http_access configuration, which could…EPSS 1.7%7.5CVE-2002-0713Squid vulnerabilityBuffer overflows in Squid before 2.4.STABLE6 allow remote attackers to cause a denial of service (crash) and possibly execute arbitrary code (1) via …EPSS 5.5%7.5CVE-2002-0714Squid vulnerabilityFTP proxy in Squid before 2.4.STABLE6 does not compare the IP addresses of control and data connections with the FTP server, which allows remote atta…EPSS 2.7%7.5CVE-2002-0163Squid vulnerabilityHeap-based buffer overflow in Squid before 2.4 STABLE4, and Squid 2.5 and 2.6 until March 12, 2002 distributions, allows remote attackers to cause a …EPSS 15%7.5CVE-2002-0067Squid vulnerabilitySquid 2.4 STABLE3 and earlier does not properly disable HTCP, even when "htcp_port 0" is specified in squid.conf, which could allow remote attackers …EPSS 3.7%

Source: NIST National Vulnerability Database (record CVE-2004-0189), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.