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.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | libfcgi-perl | 0.73-2 | — |
| Debian 13 | libfcgi-perl | 0.73-2 | — |
| Debian 12 | libfcgi-perl | 0.73-2 | — |
| Debian 6.0 | libfcgi-perl | 0.71-1+squeeze1 | DSA-2327-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | FastCGI | 2.4.0-171.10 | openSUSE-SU-2024:10387-1 |
Advisories 2
- DSA-2327-1 libfcgi-perl - authentication bypass Debian Security (DSA / DLA) · Mar 9, 2026
- openSUSE-SU-2024:10387-1 FastCGI-2.4.0-171.10 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
References
- [oss-security] 20110908 Re: CVE Request -- libfcgi-perl / perl-FCGI: Certain environment variables shared between first and subsequent HTTP requests mailing-list
- http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=607479
- [oss-security] 20110908 CVE Request -- libfcgi-perl / perl-FCGI: Certain environment variables shared between first and subsequent HTTP requests mailing-list
- perlfast-cgi-security-bypass(69709) vdb-entry
- https://bugzilla.redhat.com/show_bug.cgi?id=736604
- openSUSE-SU-2012:0036 vendor-advisory
- https://rt.cpan.org/Public/Bug/Display.html?id=68380
- 49549 vdb-entry
- openSUSE-SU-2012:0004 vendor-advisory
- DSA-2327 vendor-advisory
- MDVSA-2012:001 vendor-advisory