From Avaya Labs, a product I install on all servers and Linux based workstations, LibSafe
The exploitation of buffer overflow and format string vulnerabilities in process stacks constitutes a significant portion of security attacks in recent years. We present a new method to detect and handle such attacks. In contrast to previous work, our method does not require any modification to the operating system and works with existing binary programs. Our method does not require access to the source code of defective programs, nor does it require recompilation or off-line processing of binaries. Furthermore, it can be implemented on a system-wide basis transparently. Our solution is based on a middleware software layer that intercepts all function calls made to library functions that are known to be vulnerable. A substitute version of the corresponding function implements the original functionality, but in a manner that ensures that any buffer overflows are contained within the current stack frame, thus, preventing attackers from ‘smashing’ (overwriting) the return address and hijacking the control flow of a running program.
We have implemented our solution on Linux as a dynamically loadable library called libsafe. Libsafe has demonstrated its ability to detect and prevent several known attacks, but its real benefit, we believe, is its ability to prevent yet unknown attacks. Experiments indicate that the performance overhead of libsafe is negligible.
1 2 3 4 5 6 7 | echo "Installing LibSafe" cd /usr/local/src/ wget http://pubs.research.avayalabs.com/src/libsafe-2.0-16.tgz tar -xzvf libsafe-2.0-16.tgz cd libsafe-2.0-16/ make yes y | make install |
