stunnel: Security bypass
Gentoo Linux Security Advisory
||GLSA 200808-08 / stunnel
||August 08, 2008
||August 09, 2009: 02
All supported architectures
stunnel does not properly prevent the authentication of a revoked
certificate which would be published by OCSP.
The stunnel program is designed to work as an SSL encryption wrapper
between a remote client and a local or remote server. OCSP (Online
Certificate Status Protocol), as described in RFC 2560, is an internet
protocol used for obtaining the revocation status of an X.509 digital
An unspecified bug in the OCSP search functionality of stunnel has been
A remote attacker can use a revoked certificate that would be
successfully authenticated by stunnel. This issue only concerns the
users who have enabled the OCSP validation in stunnel.
There is no known workaround at this time.
All stunnel users should upgrade to the latest version:
Code Listing 3.1: Resolution
# emerge --sync
# emerge --ask --oneshot --verbose ">=net-misc/stunnel-4.24"