Stunnel OCSP Certificate Validation Security Bypass Vulnerability

Bugtraq ID:	29309
Class:	Design Error
CVE:	CVE-2008-2420
Remote:	Yes
Local:	No
Published:	May 19 2008 12:00AM
Updated:	Apr 16 2015 05:42PM
Credit:	Stunnel
Vulnerable:	Stunnel Stunnel 4.23 Red Hat Fedora 7 Mandriva Linux Mandrake 2008.1 x86_64 Mandriva Linux Mandrake 2008.1 Mandriva Linux Mandrake 2008.0 x86_64 Mandriva Linux Mandrake 2008.0 Mandriva Linux Mandrake 2007.1 x86_64 Mandriva Linux Mandrake 2007.1 Gentoo Linux
Not Vulnerable:	Stunnel Stunnel 4.24

Stunnel OCSP Certificate Validation Security Bypass Vulnerability

Stunnel is prone to a security-bypass vulnerability because the OCSP functionality fails to properly check revoked certificates.

Successfully exploiting this issue allows attackers to perform man-in-the-middle attacks by impersonating trusted servers and authenticating with a revoked certificate. This will aid in further attacks.

This issue affects versions prior to Stunnel 4.24.

Stunnel OCSP Certificate Validation Security Bypass Vulnerability

Currently we are not aware of any working exploits. If you feel we are in error or if you are aware of more recent information, please mail us at: [email protected].

Stunnel OCSP Certificate Validation Security Bypass Vulnerability

Solution:
Vendor updates are available. Please see the references for more information.


Stunnel Stunnel 4.23

• Stunnel stunnel-4.24.tar.gz
  ftp://stunnel.mirt.net/stunnel/stunnel-4.24.tar.gz

Stunnel OCSP Certificate Validation Security Bypass Vulnerability

References:

• [stunnel-announce] stunnel 4.24 released (Stunnel)
  
• Stunnel Homepage (Stunnel)