CVE-2021-22566 Explained : Impact and Mitigation
Learn about CVE-2021-22566, a vulnerability in the Fuchsia kernel allowing attackers to bypass executability restrictions, easing the exploitation of kernel-mode vulnerabilities. Take immediate steps to update and rebuild your kernel.
An incorrect setting of UXN and PXN bits in the Fuchsia kernel leads to privileged executable pages being mapped as executable from unprivileged and privileged contexts. This vulnerability can be exploited by an attacker to bypass executability restrictions, potentially easing the exploitation of kernel-mode vulnerabilities.
Understanding CVE-2021-22566
This CVE details the incorrect mapping of executable bits in the Fuchsia kernel, allowing attackers to circumvent security measures.
What is CVE-2021-22566?
CVE-2021-22566 addresses an issue in the Fuchsia kernel where incorrect settings of UXN and PXN bits lead to executability restrictions being bypassed.
The Impact of CVE-2021-22566
The vulnerability enables attackers to execute privileged pages from unprivileged contexts and vice versa, facilitating easier exploitation of kernel-mode vulnerabilities.
Technical Details of CVE-2021-22566
This section dives into the specifics of the vulnerability.
Vulnerability Description
The vulnerability arises from incorrect UXN and PXN bit settings, allowing unauthorized executability of kernel-mode pages from user-mode and vice versa.
Affected Systems and Versions
The Fuchsia kernel versions prior to commit 7d731b4e9599088ac3073956933559da7bca6a00 are impacted by this vulnerability.
Exploitation Mechanism
Attackers can leverage this vulnerability to bypass executability restrictions, making the exploitation of kernel-mode vulnerabilities more accessible.
Mitigation and Prevention
Learn how to protect your systems from CVE-2021-22566.
Immediate Steps to Take
It is crucial to update the Fuchsia kernel beyond commit 7d731b4e9599088ac3073956933559da7bca6a00 and rebuild to mitigate this vulnerability.
Long-Term Security Practices
Implement robust security practices such as regular updates, security monitoring, and access control to enhance system security.
Patching and Updates
Stay vigilant for security updates and patches released by Google to address CVE-2021-22566.