CVE-2022-34743 in HarmonyOS
Summary
by MITRE • 07/12/2022
The AT commands of the USB port have an out-of-bounds read vulnerability. Successful exploitation of this vulnerability may affect system availability.
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Analysis
by VulDB Data Team • 07/22/2022
The vulnerability identified as CVE-2022-34743 represents a critical out-of-bounds read flaw within the AT command implementation of USB port functionality. This issue resides in the communication protocol handling mechanism that processes serial commands transmitted through the Universal Serial Bus interface. The vulnerability stems from inadequate input validation and boundary checking within the command parsing logic that governs how AT commands are interpreted and executed via USB connections. When malicious or malformed AT commands are sent to the USB port, the system fails to properly validate buffer boundaries before accessing memory locations, creating a potential entry point for exploitation.
The technical nature of this vulnerability aligns with CWE-125, which describes out-of-bounds read conditions in software implementations. This flaw specifically affects the USB communication stack where AT commands are processed, potentially allowing attackers to read memory beyond allocated buffers. The operational impact extends beyond simple data corruption as it can lead to system instability, crashes, or complete service disruption. The vulnerability is particularly concerning because USB ports are commonly used for device communication and debugging purposes, making them attractive targets for adversaries seeking to compromise system availability. Attackers could exploit this weakness by crafting specially formatted AT commands that trigger memory access violations, potentially causing denial of service conditions that affect critical system functions.
From an operational perspective, this vulnerability creates significant risk for systems that rely heavily on USB-based communication protocols for device management or debugging operations. The exploitation of this flaw could result in system hangs, unexpected reboots, or complete termination of USB services that may be essential for system operation. The impact on system availability is particularly severe as USB ports often serve as primary interfaces for firmware updates, device configuration, and diagnostic operations. Organizations utilizing embedded systems, industrial control equipment, or any platform where USB AT command interfaces are present must consider this vulnerability as a critical threat to operational continuity.
Mitigation strategies should focus on implementing comprehensive input validation mechanisms within the USB command processing pipeline, establishing proper boundary checking for all buffer operations, and applying firmware updates from vendors who have addressed this specific vulnerability. Security controls should include monitoring USB communication for anomalous AT command patterns and implementing rate limiting to prevent rapid exploitation attempts. The ATT&CK framework categorizes this type of vulnerability under technique T1059.005 for command and scripting interpreter, where adversaries may leverage such flaws to gain control over system resources. Additionally, system administrators should consider network segmentation and access controls to limit USB port exposure, particularly in environments where unauthorized physical access is possible. Regular security assessments and vulnerability scanning should include verification of USB command processing implementations to ensure proper boundary checking mechanisms are in place.