I have problem with Tor and obfsproxy for using bridges on ubuntu 14.04. Tor could not start obfsproxy and always return permission denied.
tail -f /var/log/tor/log Aug 01 13:06:30.000 [notice] Tor 0.2.4.23 (git-05b81fcd2a655c5a) opening new log file. Aug 01 13:06:30.000 [notice] Parsing GEOIP IPv4 file /usr/share/tor/geoip. Aug 01 13:06:30.000 [notice] Parsing GEOIP IPv6 file /usr/share/tor/geoip6. Aug 01 13:06:30.000 [warn] OpenSSL version from headers does not match the version we're running with. If you get weird crashes, that might be why. (Compiled with 1000105f: OpenSSL 1.0.1e 11 Feb 2013; running with 1000106f: OpenSSL 1.0.1f 6 Jan 2014). Aug 01 13:06:33.000 [warn] Could not launch managed proxy executable at '/usr/bin/obfsproxy' ('Permission denied'). Aug 01 13:06:34.000 [notice] Bootstrapped 5%: Connecting to directory server. Aug 01 13:06:34.000 [warn] We were supposed to connect to bridge '188.8.131.52:55313' using pluggable transport 'obfs2', but we can't find a pluggable transport proxy supporting 'obfs2'. This can happen if you haven't provided a ClientTransportPlugin line, or if your pluggable transport proxy stopped running.