← Vulnerability feed

Vulnerability record · CVE-2011-2766 · published 23 September 2011

CVE-2011-2766: Fast cgi project fast cgi improper authentication vulnerability

FFast Cgi Project · Fast Cgi

The FCGI (aka Fast CGI) module 0.70 through 0.73 for Perl, as used by CGI::Fast, uses environment variable values from one request during processing of a later request, which allows remote attackers to bypass authentication via crafted HTTP headers.

7.5 CVSS 2.0 High EPSS 7.2% · top 5.9% CWE-287 · Improper authentication
7.5CVSS 2.0 base score
7.2%EPSS exploitation probability, 30 days
NoNot in CISA KEV
2Affected product versions listed by NVD
22References, 6 tagged exploit
16 Jun 2026Last modified by NVD

Description

The FCGI (aka Fast CGI) module 0.70 through 0.73 for Perl, as used by CGI::Fast, uses environment variable values from one request during processing of a later request, which allows remote attackers to bypass authentication via crafted HTTP headers.

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

Affected products

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

References

LinkTags
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=607479 ExploitIssue TrackingMailing ListThird Party Advisory
http://www.debian.org/security/2011/dsa-2327 Third Party Advisory
http://www.mandriva.com/security/advisories?name=MDVSA-2012:001 Third Party Advisory
http://www.openwall.com/lists/oss-security/2011/09/08/1 Mailing ListThird Party Advisory
http://www.openwall.com/lists/oss-security/2011/09/08/2 Mailing ListThird Party Advisory
http://www.securityfocus.com/bid/49549 Third Party AdvisoryVDB Entry
https://bugzilla.redhat.com/show_bug.cgi?id=736604 ExploitIssue TrackingThird Party Advisory
https://exchange.xforce.ibmcloud.com/vulnerabilities/69709 Third Party AdvisoryVDB Entry
https://hermes.opensuse.org/messages/13154637 Broken Link
https://hermes.opensuse.org/messages/13155253 Broken Link
https://rt.cpan.org/Public/Bug/Display.html?id=68380 ExploitPatchThird Party Advisory
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=607479 ExploitIssue TrackingMailing ListThird Party Advisory
http://www.debian.org/security/2011/dsa-2327 Third Party Advisory
http://www.mandriva.com/security/advisories?name=MDVSA-2012:001 Third Party Advisory
http://www.openwall.com/lists/oss-security/2011/09/08/1 Mailing ListThird Party Advisory
http://www.openwall.com/lists/oss-security/2011/09/08/2 Mailing ListThird Party Advisory
http://www.securityfocus.com/bid/49549 Third Party AdvisoryVDB Entry
https://bugzilla.redhat.com/show_bug.cgi?id=736604 ExploitIssue TrackingThird Party Advisory
https://exchange.xforce.ibmcloud.com/vulnerabilities/69709 Third Party AdvisoryVDB Entry
https://hermes.opensuse.org/messages/13154637 Broken Link
https://hermes.opensuse.org/messages/13155253 Broken Link
https://rt.cpan.org/Public/Bug/Display.html?id=68380 ExploitPatchThird Party Advisory

Track CVE-2011-2766 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.

10.0CVE-2025-32433Erlang/OTP SSH server missing authentication allows remote code executionErlang/OTP SSH servers before OTP-27.3.3, OTP-26.2.5.11 and OTP-25.3.2.20 mishandle SSH protocol messages, letting an unauthenticated attacker execut…KEVEPSS 99%analysed10.0CVE-2025-24201Apple WebKit out-of-bounds write allows sandbox escapeCVE-2025-24201 is an out-of-bounds write in Apple's WebKit that was addressed with improved checks. Maliciously crafted web content may break out of …KEVEPSS 3.8%analysed10.0CVE-2021-44228Apache Log4j2 JNDI lookup remote code executionApache Log4j2 versions 2.0-beta9 through 2.15.0 (excluding 2.12.2, 2.12.3, and 2.3.1) do not protect against attacker-controlled LDAP and other JNDI …KEVEPSS 100%analysed9.8CVE-2026-24061GNU Inetutils telnetd argument injection allows remote auth bypasstelnetd in GNU Inetutils through 2.7 fails to sanitize the USER environment variable, so a value such as "-f root" is passed as an argument to login …KEVEPSS 99%analysed9.8CVE-2025-39682Linux kernel TLS zero-length record handling flaw on rx_listThe Linux kernel TLS receive path mishandles zero-length records that arrive from the rx_list, breaking the assumption that a record type change cann…KEVEPSS 2.9%analysed9.8CVE-2025-24813Apache Tomcat Default Servlet path equivalence enables RCE and file disclosureApache Tomcat mishandles path equivalence for names containing an internal dot, letting a remote unauthenticated attacker write files through the Def…KEVEPSS 100%analysed9.8CVE-2024-9680Mozilla Firefox and Thunderbird use-after-free in Animation timelinesA use-after-free flaw in Animation timelines allows an attacker to execute code in the content process of Firefox and Thunderbird. Mozilla reports ex…KEVEPSS 23%analysed9.8CVE-2023-46604Apache ActiveMQ OpenWire deserialization remote code executionThe Java OpenWire protocol marshaller in Apache ActiveMQ deserializes untrusted data, letting an attacker manipulate serialized class types so the br…KEVEPSS 100%analysed

Source: NIST National Vulnerability Database (record CVE-2011-2766), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.