A hardware flaw in Intel Core and Xeon CPUs lets attackers steal data from other users on the same system, including on servers that use Intel’s SGX memory protections, according to a Google researcher.
According to SC Magazine, Daniel Moghimi told the Black Hat 2023 security conference this week that the vulnerability, dubbed “Downfall”, endangers data running on virtual machines or in containers in shared environments, such as in most cloud-computing deployments, as well as on personal computers with multiple users. The flaw is also known as CVE-2022-40982.
A malicious app obtained from an app store could use the Downfall attack to steal sensitive information like passwords, encryption keys, and private data such as banking details, personal emails, and messages, Moghimi wrote on the Downfall information website. Similarly, he said, in cloud computing environments, a malicious customer could exploit the Downfall vulnerability to steal data and credentials from other customers who share the same cloud computer.
The vulnerability is caused by memory optimization features in Intel processors that unintentionally reveal internal hardware registers to software. This allows untrusted software to access data stored by other programs, which should not normally be accessible.
Computing devices based on Intel Core processors from the 6th generation Skylake — released in 2014 — to the 11th generation Tiger Lake are affected, the website says.
“It took me two weeks to develop an end-to-end attack stealing encryption keys from OpenSSL,” Moghimi said. “It only requires the attacker and victim to share the same physical processor core, which frequently happens on modern-day computers, implementing preemptive multitasking and simultaneous multithreading.”
Intel is releasing a microcode update that blocks transient results of the exploit Moghimi created. However, the information site says, according to Intel some workloads may experience up to a 50 per cent performance hit.
