env t='() { :;}; echo You are vulnerable.' bash -c "true"
如显示You are vulnerable，很遗憾，必须立即打上安全补丁修复

wget http://ftp.gnu.org/gnu/bash/bash-4.3.tar.gz
tar zxf bash-4.3.tar.gz ; cd bash-4.3
wget -r -nd -np http://ftp.gnu.org/gnu/bash/bash-4.3-patches/
for BP in `ls bash43-*|grep -v sig`; do patch -p0 < $BP; done ./configure make && make install

url：http://seclists.org/oss-sec/2014/q3/650