Intel and AMD chips are yet to be prone to another Spectre-based speculative execution called the Retbleed campaign. Based on reports, both impacted companies have started releasing several threat mitigation measures to prevent the new threat campaign from infecting their customers’ chips.
According to a research group, the threat actors could abuse two newly discovered flaws of Retbleed, which could acquire sensitive data and passwords from the memory of their targeted device.
Researchers tracked these vulnerabilities as CVE-2022-29900 and CVE-2022-29901. Both exploits could impact outdated or older chips from Intel and AMD – AMC Zen 1, Zen 1+, Zen 2, and Intel Core generation 6-8.
Researchers deemed this new campaign the most recent side-channel attack discovered in less than a month. According to them, the appearance of these attacks is very threatening for users since another attack called Hertzbleed appeared just weeks ago.
In addition, this new threat campaign bypasses the Retpolines defence system that its operators disclosed in 2018 to prevent a specific attack called Spectre-Branch Target Injection attacks or BTI.
Researchers elaborated that the attacks are unlike their past strains activated by abusing an indirect call or jump. However, Retbleed takes advantage of return instructions to undermine the BTI defences.
Retbleed and Hertzbleed may be the same.
A separate researcher noticed that the Retbleed attack came quickly right after the Hertzbleed attack a few weeks ago. However, the latter exploited a different flaw in the modern chips of AMD and Intel.
The exploit could allow an adversary to extract cryptographic keys from remote servers by monitoring in CPU frequency activated by (DVFS). Unfortunately, there is no available patch or mitigations for the attacks, but companies have given workarounds to secure the affected chips.
AMD and Intel have recently released threat advisories for their clients while developers are processing fixes for major Linux distributions.
Intel is closely working with the VMM and Linux vendors to give its customers the software mitigation guidelines. AMD has also suggested that software suppliers consider taking more steps in helping them counteract Spectre-based attacks.
