OpenVPN 2.0 through 2.0.5 allows remote malicious servers to execute arbitrary code on the client by using setenv with the LD_PRELOAD environment variable.
https://exchange.xforce.ibmcloud.com/vulnerabilities/25667
http://www.vupen.com/english/advisories/2006/1261
http://www.securityfocus.com/bid/17392
http://www.osreviews.net/reviews/security/openvpn-print
http://www.novell.com/linux/security/advisories/2006_04_28.html
http://www.mandriva.com/security/advisories?name=MDKSA-2006:069
http://www.debian.org/security/2006/dsa-1045
http://sourceforge.net/mailarchive/forum.php?thread_id=10093825&forum_id=8482
http://secunia.com/advisories/19897
http://secunia.com/advisories/19837
http://secunia.com/advisories/19598