CVE-2021-22566
Published: 18 January 2022
Summary
CVE-2021-22566 is a medium-severity Incorrect Permission Assignment for Critical Resource (CWE-732) vulnerability in Google Fuchsia. Its CVSS base score is 5.1 (Medium).
Operationally, ranked at the 3.0th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2021-9705
Vulnerability details
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…
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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.
- CWE(s)
Related Threats
No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.
Affected Assets
Mitigating Controls
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Procedures support proper permission assignment for critical resources through documented controls.
Attribute management for resources provides a mechanism to assign and maintain correct permissions based on security labels.
Prevents overly permissive assignments to critical resources by limiting to task needs.
Training policy covers correct permission assignment, reducing the ability to exploit incorrect permission assignments for critical resources.
Training on permission management reduces incorrect permission assignments for critical resources.
Audit logs and logging tools are critical resources whose protection requires correct permission assignments to block unauthorized actions.
Assessments review permission assignments on critical resources to confirm correctness, mitigating exploitation via incorrect permissions.
Certification includes checking that permissions on critical resources are correctly assigned.