CVE-2023-20661 in MT5221
Summary
by MITRE • 04/06/2023
In wlan, there is a possible out of bounds write due to an integer overflow. This could lead to local escalation of privilege with System execution privileges needed. User interaction is not needed for exploitation. Patch ID: ALPS07560782; Issue ID: ALPS07560782.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 08/29/2025
The vulnerability identified as CVE-2023-20661 resides within the wireless local area network component of a mobile operating system, specifically affecting the wlan module. This issue represents a critical security flaw that stems from improper handling of integer values during memory allocation processes. The vulnerability manifests as an out-of-bounds write condition that occurs when an integer overflow takes place, allowing malicious code to potentially overwrite adjacent memory locations. The flaw exists in the wireless networking subsystem where data structures are manipulated without adequate bounds checking mechanisms, creating opportunities for exploitation that can result in system compromise.
The technical root cause of this vulnerability can be classified as a CWE-129 weakness, specifically an insufficient bounds checking scenario that leads to memory corruption. When processing wireless network data packets or configuration parameters, the wlan module fails to properly validate integer values before using them as array indices or memory allocation sizes. This integer overflow condition occurs when a calculation exceeds the maximum value that can be represented by the integer data type, causing the value to wrap around to a much smaller number. The resulting corrupted integer value then gets used to determine memory allocation or array indexing operations, leading to unauthorized memory access patterns that can be exploited for privilege escalation.
The operational impact of this vulnerability extends beyond simple memory corruption, as it provides a pathway for local privilege escalation attacks that can elevate process privileges from regular user level to system level execution. Attackers can leverage this flaw to execute arbitrary code with elevated privileges, potentially gaining complete control over the device's wireless networking capabilities and underlying system resources. The exploitation does not require user interaction, making it particularly dangerous as it can be triggered automatically when the affected wlan module processes certain network data or configuration inputs. This autonomous exploitation capability significantly increases the attack surface and potential for widespread compromise across devices running vulnerable software versions.
Security mitigations for this vulnerability should focus on implementing robust input validation and bounds checking mechanisms within the wlan module's data processing pipelines. The patch ALPS07560782 addresses this issue by introducing proper integer overflow detection and handling procedures that prevent maliciously crafted inputs from causing memory corruption. System administrators should prioritize applying the vendor-provided security update immediately to protect against potential exploitation attempts. Additional defensive measures include implementing memory protection mechanisms such as stack canaries, address space layout randomization, and control flow integrity checks to further reduce the effectiveness of potential exploitation attempts. Organizations should also monitor for related vulnerabilities in similar networking components and maintain updated threat intelligence to identify potential variants or related attack patterns that may target the same class of vulnerabilities.