If your apt-get repositories don’t contains any precompiled 1.0.1g OpenSSL version, so just download sources from official website and compile it.
Below the single command line to compiling and install the last openssl version.
curl https://www.openssl.org/source/openssl-1.0.1g.tar.gz | tar xz && cd openssl-1.0.1g && sudo ./config && sudo make && sudo make install
Replace old openssl binary file by the new one via a symlink.
sudo ln -sf /usr/local/ssl/bin/openssl `which openssl`
You are all good !
# openssl version should return openssl version OpenSSL 1.0.1g 7 Apr 2014