OpenSSH to protect keys in memory against side-channel attacks
1 min read
Jul 02, 2019
The OpenSSH project has received a patch that prevents private keys from being stolen through hardware vulnerabilities that allow hackers to access restricted memory regions from unprivileged processes. The same approach could be used by other software application to protect their secrets in RAM until the issues are fixed in future generations of SDRAM chips and CPUs.
The patch comes after a team of researchers recently presented an attack dubbed RAMBleed that exploits the design of modern memory modules in to extract information from memory regions allocated to privileged processes and the kernel.
RAMBleed uses a software technique called Rowhammer to trigger bit flips inside physical memory cells and then recover sensitive information through a side channel. The researchers demonstrated their attack by recovering an RSA 2048-bit signing key from an OpenSSH server using code running with user-level privileges.
