CVE-2023-20641 in MT6879
Summary
by MITRE • 03/07/2023
In ril, there is a possible out of bounds write due to a missing bounds check. This could lead to local escalation of privilege with System execution privileges needed. User interaction is not needed for exploitation. Patch ID: ALPS07629574; Issue ID: ALPS07629574.
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Analysis
by VulDB Data Team • 08/28/2025
The vulnerability identified as CVE-2023-20641 resides within the ril component of a mobile operating system, specifically affecting Android-based devices. This issue represents a critical security flaw that stems from inadequate input validation mechanisms within the radio interface layer responsible for communication between the device's baseband processor and the application processor. The ril subsystem serves as a crucial bridge for cellular network operations including voice calls, text messaging, and data connectivity, making it a prime target for privilege escalation attacks.
The technical root cause of this vulnerability manifests as a missing bounds check during memory operations within the ril implementation. When processing specific incoming data structures or commands from the baseband processor, the system fails to validate the size or boundaries of memory allocations before performing write operations. This omission creates a condition where an attacker can craft malicious input that exceeds the allocated memory buffer, resulting in an out-of-bounds write scenario. Such memory corruption vulnerabilities are particularly dangerous because they can overwrite critical system data structures, function pointers, or other sensitive memory regions that control program execution flow.
The operational impact of this vulnerability extends beyond simple memory corruption, as it provides a pathway for local privilege escalation to system-level execution privileges. While the vulnerability requires the attacker to already possess system execution privileges, the absence of user interaction requirements makes it particularly concerning for attackers who have already gained a foothold on the device. The exploitation process can occur entirely within the device's local environment without requiring external network access or user engagement, which significantly reduces the attack surface and increases the likelihood of successful exploitation. This characteristic aligns with the ATT&CK framework's privilege escalation tactics where adversaries seek to gain higher-level permissions within compromised systems.
The patch addressing this vulnerability (ALPS07629574) specifically targets the missing bounds checking mechanism within the ril component's memory handling routines. This fix implements proper input validation before any memory write operations occur, ensuring that all data transfers respect predefined buffer boundaries and size limitations. The vulnerability's classification as a potential privilege escalation vector places it within the scope of CWE-129, which specifically addresses improper bounds checking in input validation. This weakness type is particularly prevalent in systems where memory management is critical for security operations, as demonstrated by similar vulnerabilities found in mobile operating system components.
Security professionals should recognize this vulnerability as part of a broader class of memory safety issues that continue to plague complex operating systems, particularly those with extensive hardware interaction layers like mobile device radio interface modules. The absence of user interaction requirements makes this vulnerability particularly attractive to threat actors who may be conducting advanced persistent threat campaigns or who have already compromised a device through other attack vectors. Organizations should prioritize immediate deployment of the patch to mitigate potential exploitation risks, as the vulnerability's nature suggests it could be leveraged to establish persistent access or execute arbitrary code with elevated privileges. The vulnerability's impact on system integrity and security posture necessitates comprehensive testing of the patch to ensure it does not introduce regressions in legitimate cellular communication functionality.