`Shellshock` bash vulnerability fix and update in case of slow or unavailable repositories

Updated to latest kernel patch bash43-30

You’ve heard of ShellShock, and the bash-exploits that are currently doing the rounds, across platforms, that make use of these bugs (CVE-2014-6271 and the volumes of additional updates including CVE-2014-6277, CVE-2014-7186, CVE-2014-7187 and CVE-2014-7169, but to name a few). Proofs of Concept are being collected here… The below works as a vulnerability fix for older Ubuntu LTS and non-LTS versions, Debian (eg Squeeze) as well as Fedora and RedHat/CentOS, and applies all up-to-date patches to Bash.

bash – as a shell – is a tried and trusted component. Some legacy systems’ repositories – be they apt, yum or other – may no longer be kept up to date. Alternatively, they may not be being kept up-to-date enough for your liking. And you want to close the bash issue in the best way you know how.

Easy workaround is a recompile of the bash shell yourself:

Depending on the system you are using, you may need to do this outside the environment you want to install bash on as it may not be on a compiler-enabled system.

The below is valid for all patches as at 5 Oct 2014:

mkdir src
cd src
wget http://ftp.gnu.org/gnu/bash/bash-4.3.tar.gz
#download all patches
for i in $(seq -f "%03g" 1 30); do wget http://ftp.gnu.org/gnu/bash/bash-4.3-patches/bash43-$i; done
tar zxvf bash-4.3.tar.gz
cd bash-4.3
#apply all patches
for i in $(seq -f "%03g" 1 30);do patch -p0 < ../bash43-$i; done
#build and install
./configure --prefix=/ && make && make install
cd ..
cd ..
rm -r src

Good rule would be to make a copy of /bin/bash first, in case something doesn’t work out.

But you knew that already.

Kudos to Hackernews, SuperUser and updates.

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