Intel has publically disclosed three new Spectre-like vulnerabilities, calling them L1 Terminal Fault (L1TF), that can be exploited to steal secret information from the computer memory.
The new vulnerabilities affect Intel’s desktop, workstation, and server CPUs and can be used to lift secret information like passwords, personal and financial data, as well as encryption keys from applications, virtual machines, SGX enclaves, and System Management Mode (SMM) memory.
The biggest issue is exactly the flaw affecting Intel SGX, so-called Foreshadow vulnerability, which is the first time that Intel SGX has been affected since it was mostly unaffected by earlier Meltdown and Spectre vulnerabilities.
The new L1 Terminal Fault (L1TF) vulnerabilities include the CVE-2018-3615, which is the one targeting Intel’s Software Guard Extensions (SGX), the CVE-2018-3620, which affects System Management Mode (SMM) memory, and the CVE-2018-3646, which affects hypervisors and virtual machines.
Intel has already released mitigations for the L1TF vulnerabilities and has noted that these work best with microcode updates for Meltdown and Spectre, released earlier this year.
In a post regarding the new L1 Terminal Fault (L1TF) vulnerabilities, Leslie Culbertson, Intel’s executive vice president and general manager of product assurance and security said that: “Once systems are updated, we expect the risk to consumer and enterprise users running non-virtualized operating systems will be low”.
Google also released a blog post regarding the L1TF vulnerabilities, stating that Foreshadow is the biggest concern.
“Defending against this method of attack is particularly challenging for virtualized environments, as a virtual machine exposes the state necessary to construct an attack. Specifically, an attacker could intentionally configure their own page tables to direct these faults and probe the cache of the core on which they are currently executing.”
Hopefully, the new vulnerabilities plaguing Intel CPUs will not have a big impact but it appears that Intel was lucky that some of those microcodes updates released earlier this year, as well as current updates to operating system and hypervisor software, should mitigate the issue.