CVE-2022-20409 in Android
Summary
by MITRE • 10/12/2022
In io_identity_cow of io_uring.c, there is a possible way to corrupt memory due to a use after free. This could lead to local escalation of privilege with System execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android kernelAndroid ID: A-238177383References: Upstream kernel
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Analysis
by VulDB Data Team • 04/13/2026
The vulnerability identified as CVE-2022-20409 resides within the io_uring subsystem of the Android kernel, specifically in the io_identity_cow function located in io_uring.c. This represents a critical use after free condition that can potentially lead to local privilege escalation, requiring system execution privileges for exploitation. The flaw manifests in how the kernel handles memory management during io_uring operations, creating a scenario where freed memory regions can be accessed and modified by subsequent operations. The vulnerability is particularly concerning as it operates within the kernel space, where memory corruption can directly compromise system integrity and enable unauthorized privilege elevation. This type of vulnerability falls under the Common Weakness Enumeration category CWE-416, which specifically addresses use after free conditions that occur when a program continues to use a pointer after the memory it points to has been freed. The attack vector requires local system access, meaning an attacker must already have user-level privileges to exploit this vulnerability, but successful exploitation would grant them escalated privileges to execute code with system-level permissions.
The operational impact of this vulnerability extends beyond simple memory corruption, as it creates a pathway for persistent system compromise through local privilege escalation. When the io_identity_cow function encounters a use after free scenario, it can lead to arbitrary code execution within kernel space, potentially allowing attackers to bypass security boundaries and gain unauthorized access to critical system resources. The memory corruption can manifest in various ways including overwriting kernel data structures, manipulating process control blocks, or corrupting kernel function pointers, all of which can result in system instability or complete compromise. From an attack perspective, this vulnerability aligns with the MITRE ATT&CK framework's privilege escalation techniques, specifically targeting the execution of malicious code with elevated privileges. The lack of user interaction requirement for exploitation makes this particularly dangerous as it can be leveraged by malicious applications or processes running on the device without additional user consent or intervention.
Mitigation strategies for CVE-2022-20409 should focus on immediate kernel updates and patches provided by Android security teams, as the upstream kernel has addressed this issue through proper memory management handling in the io_uring subsystem. System administrators and device manufacturers should prioritize deploying these patches to prevent exploitation, particularly on devices running vulnerable Android kernel versions. Additionally, implementing runtime protections such as kernel address space layout randomization kASLR and stack canaries can provide defense-in-depth measures against potential exploitation attempts. Monitoring for unusual kernel memory access patterns or suspicious io_uring operations can also help detect potential exploitation attempts. Organizations should also consider implementing application sandboxing and privilege separation mechanisms to limit the potential impact of any successful exploitation attempts. The vulnerability highlights the importance of rigorous code review processes for kernel subsystems and proper memory management practices, particularly in high-risk areas such as io_uring that handle asynchronous I/O operations and require careful handling of shared memory resources. Regular security audits and fuzzing of kernel subsystems can help identify similar vulnerabilities before they can be exploited in the wild.