CVE-2022-33294 in 9205 LTE Modem
Summary
by MITRE • 04/13/2023
Transient DOS in Modem due to NULL pointer dereference while receiving response of lwm2m registration/update/bootstrap request message.
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Analysis
by VulDB Data Team • 04/13/2023
This vulnerability represents a critical transient denial of service condition affecting modem firmware systems that process lwm2m protocol messages. The flaw manifests as a null pointer dereference during the reception of lwm2m registration, update, or bootstrap request responses, creating a scenario where legitimate network operations can be disrupted through carefully crafted malicious payloads. The vulnerability exists within the modem's communication processing stack where incoming lwm2m messages are parsed and handled, specifically during the response handling phase of lwm2m operations that are fundamental to device management and provisioning in IoT environments.
The technical implementation of this vulnerability stems from inadequate input validation and error handling within the modem's lwm2m message processing subsystem. When a modem receives a response message containing malformed or unexpected data structures during lwm2m registration, update, or bootstrap procedures, the processing code fails to properly check for null pointer references before attempting to dereference pointers that may be uninitialized or explicitly set to null. This condition typically occurs in the message parsing and validation logic where the modem attempts to access response fields or metadata without proper null checks, leading to immediate system termination or crash conditions that result in complete service disruption for the affected device.
The operational impact of this vulnerability extends beyond simple service interruption to encompass broader network reliability and security concerns within IoT ecosystems. Devices that rely on lwm2m for device management and provisioning become vulnerable to targeted denial of service attacks that can render them inoperable until manual intervention or power cycling occurs. This vulnerability particularly affects cellular IoT devices, industrial sensors, and smart metering systems where modem availability is critical for network connectivity and operational continuity. The transient nature of the denial of service means that affected devices may recover automatically upon reboot, but the window of service disruption can be significant enough to impact mission-critical applications and cause cascading failures in connected systems.
Mitigation strategies for this vulnerability should focus on implementing robust input validation and defensive programming practices within modem firmware implementations. Firmware vendors should ensure that all pointer dereferences are preceded by proper null checks and that error handling routines are implemented to gracefully process malformed or unexpected message content. The fix should include comprehensive validation of lwm2m response message structures before any processing occurs, with proper error codes returned for invalid inputs rather than allowing system crashes to occur. Additionally, network operators should consider implementing monitoring solutions that can detect anomalous lwm2m message patterns that might indicate exploitation attempts. This vulnerability aligns with CWE-476 which describes null pointer dereference conditions, and could be categorized under ATT&CK technique T1499.001 for network denial of service attacks. Organizations should prioritize firmware updates from vendors and implement network segmentation to limit the potential impact of exploitation attempts.