Intel disclosed a series of vulnerabilities on July 10, including new variants of the Spectre vulnerability the company has been dealing with since January.
Two new Spectre variants were discovered by security researchers Vladimir Kiriansky and Carl Waldspurger, who detailed their findings in a publicly released research paper tilted, “Speculative Buffer Overflows: Attacks and Defenses.”
“We introduce Spectre1.1, a new Spectre-v1 variant that leverages speculative stores to create speculative buffer over-flows,” the researchers wrote. “We also present Spectre 1.2 on CPUs that do not enforce read/write protections, speculative stores can overwrite read-only data and code pointers to breach sandboxes.”
Intel publicly reported the initial round of Meltdown and Spectre CPU flaws on Jan. 3. Multiple additional variants have been reported in the months since, including two flaws on May 21 and a Lazy Restore Speculative execution risk disclosed on June 13. The Spectre flaws abuse the speculative execution feature in modern CPUs, which aims to accelerate performance by speculating what the next instruction will be. The new Spectre 1.1 and Spectre 1.2 variants have been given the CVE-2018-3693 identifier and are rated as being high impact, with a Common Vulnerability Scoring System (CVSS) score of 7.1.
“Systems with microprocessors utilizing speculative execution and branch prediction may allow unauthorized disclosure of information to an attacker with local user access via a speculative buffer overflow and side-channel analysis,” Intel warns in an advisory.
The new CVE-2018-3693 issues were reported to Intel via the company’s bug bounty program, which is hosted by managed bug bounty provider HackerOne. While full details are not currently publicly available on HackerOne’s platform, the Intel bug bounty page indicates that Kiriansky (vik) was paid $100,000 for a bug report.
Mitigations
Intel has already released mitigations for most of the Spectre and Meltdown variants and has publicly stated that it is working on hardware improvements to help prevent future issues as well.
“Along with other companies whose platforms are potentially impacted by these new methods, including AMD and ARM, Intel has worked with operating system vendors, equipment manufacturers, and other ecosystem partners to develop software updates or developer guidance that can help protect systems from these methods,” Intel stated in its advisory. “End users and systems administrators should check with their operating system vendors and apply any available updates as soon as practical.”
The importance of hardware-based innovation to help reduce the risk for Spectre attacks is something that Kiriansky and Waldspurger’s report also highlights.
“If we must rely on software mitigations that require developers to manually reason about the necessity of mitigations, we may face decades of speculative-execution attacks,” the paper states.
Although side-channel speculative attack vulnerabilities related to Meltdown and Spectre have been known since January, wide-scale attacks are not currently being reported. A recent report from SonicWall found that in the first half of 2018, there were no attacks that directly made use of Meltdown and Spectre vulnerabilities.
Sean Michael Kerner is a senior editor at eWEEK and InternetNews.com. Follow him on Twitter @TechJournalist.