CVE-2021-26342 Information disclosure in EPYC™ Processors
A CPU microcode flaw in AMD EPYC processors may allow disclosure of SEV guest memory contents due to stale TLB translations.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2021-26342?
CVE-2021-26342 is a low-severity vulnerability in Amd Epyc 72f3 Firmware, published on 11 May 2022. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In SEV guest VMs, the CPU may fail to flush the Translation Lookaside Buffer (TLB) following a particular sequence of operations that includes creation of a new virtual machine control block (VMCB). The failure to flush the TLB may cause the microcode to use stale TLB translations which may allow for disclosure of SEV guest memory contents. Users of SEV-ES/SEV-SNP guest VMs are not impacted by this vulnerability.
Which versions are affected by CVE-2021-26342?
It affects 38 products.
Products include Amd Epyc 7001 Firmware, Amd Epyc 7251 Firmware, Amd Epyc 7261 Firmware, Amd Epyc 7281 Firmware, Amd Epyc 72f3 Firmware, Amd Epyc 7301 Firmware and 32 more.
How do I fix CVE-2021-26342?
Apply the vendor's patch.
Is CVE-2021-26342 being exploited?
There is no known exploitation of CVE-2021-26342 in the wild and no public exploit code.
Other vulnerabilities in Amd Epyc 72f3 Firmware
- CVE-2021-26340 A malicious hypervisor in conjunction with an unprivileged attacker process inside an SEV/SEV-ES guest VM may fail to flush the Translation
- CVE-2021-26398 Memory corruption in 1st Gen EPYC
- CVE-2021-26331 Code injection in 1st Gen AMD EPYC™
- CVE-2021-26335 Code injection in Athlon™ Series
- CVE-2023-20578 Race condition in AMD EPYC™ 7001 Processors
Sources
Also known as GHSA-wp53-p3r5-cq4w.