← Vulnerability feed

Vulnerability record · CVE-2009-0801 · published 4 March 2009

CVE-2009-0801: Squid web proxy cache permissions and access controls vulnerability

Squid · Squid Web Proxy Cache

Squid, when transparent interception mode is enabled, uses the HTTP Host header to determine the remote endpoint, which allows remote attackers to bypass access controls for Flash, Java, Silverlight, and probably other technologies, and possibly communicate with restricted intranet sites, via a crafted web page that causes a client to send HTTP requests with a modified Host header.

5.4 CVSS 2.0 Medium EPSS 3.1% · top 12.8% CWE-264 · Permissions and access controls
5.4CVSS 2.0 base score
3.1%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
4References
16 Jun 2026Last modified by NVD

Description

Squid, when transparent interception mode is enabled, uses the HTTP Host header to determine the remote endpoint, which allows remote attackers to bypass access controls for Flash, Java, Silverlight, and probably other technologies, and possibly communicate with restricted intranet sites, via a crafted web page that causes a client to send HTTP requests with a modified Host header.

AV:N/AC:H/Au:N/C:C/I:N/A:N

Affected products

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

References

LinkTags
http://www.kb.cert.org/vuls/id/435052 Third Party AdvisoryUS Government Resource
http://www.securityfocus.com/bid/33858
http://www.kb.cert.org/vuls/id/435052 Third Party AdvisoryUS Government Resource
http://www.securityfocus.com/bid/33858

Track CVE-2009-0801 inside VULONE

Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.

Start free Open in platform

Related vulnerabilities

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

5.0CVE-2007-6239Squid web proxy cache improper input validation vulnerabilityThe "cache update reply processing" functionality in Squid 2.x before 2.6.STABLE17 and Squid 3.0 allows remote attackers to cause a denial of service…EPSS 27%5.1CVE-2015-3246libuser userhelper direct /etc/passwd write race conditionlibuser before 0.56.13-8 and 0.60 before 0.60-7, as used by the userhelper program in the usermode package, modifies /etc/passwd directly instead of …KEVEPSS 8.8%analysed6.6CVE-2015-1769Windows Mount Manager symlink mishandling allows local privilege escalationThe Windows Mount Manager mishandles symbolic links, allowing a crafted USB device to trigger arbitrary code execution. Because the flaw is in a core…KEVEPSS 4.1%analysed7.8CVE-2016-3643SolarWinds Virtualization Manager sudo misconfiguration privilege escalationSolarWinds Virtualization Manager 6.3.1 and earlier ship with a misconfigured sudo policy that lets a local user run privileged commands, as shown by…KEVEPSS 3.7%analysed

Source: NIST National Vulnerability Database (record CVE-2009-0801), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.