FreeBSD VuXML: Documenting security issues in FreeBSD and the FreeBSD Ports Collection

openvpn -- LD_PRELOAD code execution on client through malicious or compromised server

Affected packages
2.0 <= openvpn < 2.0.6


VuXML ID be4ccb7b-c48b-11da-ae12-0002b3b60e4c
Discovery 2006-04-03
Entry 2006-04-05
Modified 2006-04-06

Hendrik Weimer reports:

OpenVPN clients are a bit too generous when accepting configuration options from a server. It is possible to transmit environment variables to client-side shell scripts. There are some filters in place to prevent obvious nonsense, however they don't catch the good old LD_PRELOAD trick. All we need is to put a file onto the client under a known location (e.g. by returning a specially crafted document upon web access) and we have a remote root exploit. But since the attack may only come from authenticated servers, this threat is greatly reduced.


CVE Name CVE-2006-1629