CVE-2023-20693 in MT6739
Summary
by MITRE • 07/04/2023
In wlan firmware, there is possible system crash due to an uncaught exception. This could lead to remote denial of service with no additional execution privileges needed. User interaction is not needed for exploitation. Patch ID: ALPS07664711; Issue ID: ALPS07664711.
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Analysis
by VulDB Data Team • 07/22/2023
The vulnerability identified as CVE-2023-20693 resides within the wireless local area network firmware of a mobile device platform, specifically affecting the wlan firmware component. This issue manifests as an unhandled exception that can trigger a system crash under certain conditions. The flaw represents a critical weakness in the firmware's error handling mechanisms, where the system fails to properly manage exceptional circumstances during wireless communication processing. The vulnerability is particularly concerning because it operates at the firmware level, which sits below the operating system layer and controls fundamental hardware functions. This low-level positioning means that the impact extends beyond typical software applications and can affect the entire device's operational stability. The vulnerability has been assigned a patch identifier ALPS07664711 and issue identifier ALPS07664711, indicating it was addressed within a specific firmware update cycle for Android-based platforms. The absence of user interaction requirements for exploitation makes this vulnerability particularly dangerous as it can be triggered remotely without any user involvement or specialized privileges.
The technical flaw stems from inadequate exception handling within the wlan firmware code structure, where specific error conditions are not properly caught and managed during wireless protocol processing. When certain malformed wireless packets or unexpected communication states occur, the firmware fails to gracefully handle these exceptional conditions, resulting in an abrupt system termination or crash. This behavior aligns with CWE-440, which addresses the lack of proper error handling in network protocols, and CWE-704, which deals with incorrect error handling that leads to system instability. The uncaught exception mechanism typically occurs when the firmware encounters data or communication patterns that exceed expected parameters or fall outside defined protocol boundaries. The vulnerability demonstrates characteristics consistent with the attack pattern described in ATT&CK technique T1499.004, which involves network denial of service attacks through exploitation of system vulnerabilities. The firmware's failure to implement robust exception handling protocols means that any malicious actor capable of sending specific wireless packets or triggering particular communication scenarios can induce the system crash, regardless of their privilege level or physical access requirements.
The operational impact of CVE-2023-20693 extends beyond simple device instability to potentially compromise the overall security posture of affected devices. When the wlan firmware crashes, it can result in complete device unresponsiveness, requiring manual reboot or power cycle to restore functionality. This denial of service condition can persist until the device is restarted, potentially disrupting critical communications or services that depend on wireless connectivity. The vulnerability affects devices that utilize the specific firmware version containing the unhandled exception, which typically includes various smartphone models, tablets, and potentially IoT devices running affected firmware versions. The remote exploitation capability means that attackers can trigger the vulnerability from outside the device's physical boundaries, making it particularly dangerous in environments where wireless communications are prevalent. The lack of privilege requirements for exploitation indicates that even unauthenticated attackers can potentially cause service disruption, making this vulnerability attractive for attackers seeking to perform denial of service attacks without significant technical expertise or access privileges. The impact is further amplified by the fact that wlan connectivity is often essential for device functionality, making the service disruption potentially severe.
Mitigation strategies for CVE-2023-20693 should prioritize the immediate application of the vendor-provided patch ALPS07664711, which addresses the underlying exception handling flaw in the wlan firmware. Organizations and individuals should ensure that all affected devices receive the firmware update as soon as possible, particularly those in environments where wireless connectivity is critical for operations. The patch implementation should be performed through official channels to ensure the authenticity of the update and avoid potential supply chain attacks. System administrators should monitor device firmware versions and implement automated update mechanisms where possible to maintain consistent protection across device fleets. Additional defensive measures include implementing network monitoring to detect unusual wireless traffic patterns that might indicate exploitation attempts, and establishing incident response procedures for handling device crashes or service disruptions. The vulnerability highlights the importance of robust firmware security practices and proper error handling mechanisms, which should be incorporated into all firmware development processes. Organizations should also consider implementing network segmentation and access controls to limit the potential impact of such vulnerabilities, particularly in enterprise environments where device compromise could affect broader network security. Security teams should conduct regular vulnerability assessments to identify similar unhandled exception patterns in other firmware components and ensure comprehensive protection against similar threats.