CVE-2021-22566 Incorrect mapping of Executable bits in Fuchsia Kernel
Incorrect MMU flag mapping allows bypassing kernel and user-mode executability restrictions, facilitating privilege escalation in Fuchsia OS.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2021-22566?
CVE-2021-22566 is a medium-severity vulnerability in Google LLC Fuchsia, published on 18 Jan 2022. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
An incorrect setting of UXN bits within mmu_flags_to_s1_pte_attr lead to privileged executable pages being mapped as executable from an unprivileged context. This can be leveraged by an attacker to bypass executability restrictions of kernel-mode pages from user-mode. An incorrect setting of PXN bits within mmu_flags_to_s1_pte_attr lead to unprivileged executable pages being mapped as executable from a privileged context. This can be leveraged by an attacker to bypass executability restrictions of user-mode pages from kernel-mode. Typically this allows a potential attacker to circumvent a mitigation, making exploitation of potential kernel-mode vulnerabilities easier. We recommend updating kernel beyond commit 7d731b4e9599088ac3073956933559da7bca6a00 and rebuilding.
Which versions are affected by CVE-2021-22566?
It affects 1 product.
Products include Google Fuchsia.
How do I fix CVE-2021-22566?
No fix has been published for CVE-2021-22566 yet. Limit exposure of the affected software until one is available.
Is CVE-2021-22566 being exploited?
There is no known exploitation of CVE-2021-22566 in the wild and no public exploit code.
Other vulnerabilities in Google LLC Fuchsia
Sources
Also known as GHSA-q77g-rg5g-rf78.