CVE-2024-20003 in MT2735
Summary
by MITRE • 02/05/2024
In Modem NL1, there is a possible system crash due to an improper input validation. This could lead to remote denial of service, if NW sent invalid NR RRC Connection Setup message, with no additional execution privileges needed. User interaction is not needed for exploitation. Patch ID: MOLY01191612; Issue ID: MOLY01191612 (MSV-981).
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 02/25/2024
The vulnerability identified as CVE-2024-20003 affects the Modem NL1 component and represents a critical denial of service weakness stemming from inadequate input validation mechanisms. This flaw specifically manifests when the modem receives a malformed NR RRC Connection Setup message from the network side, creating a scenario where the device becomes unresponsive or crashes entirely. The vulnerability resides within the modem's radio resource control processing logic, where insufficient validation of incoming connection setup parameters allows malicious or malformed data to trigger system instability. The issue is particularly concerning as it operates without requiring any special privileges or user interaction, making it highly exploitable in remote scenarios where an attacker could potentially disrupt service availability.
The technical implementation of this vulnerability demonstrates a classic input validation flaw that aligns with CWE-20, which describes improper input validation as a fundamental weakness in software design. When the modem receives an invalid NR RRC Connection Setup message, the system fails to properly sanitize or validate the incoming data structure before processing, leading to a potential buffer overflow or invalid memory access condition. This processing failure occurs at the network radio resource control layer where the modem handles 5G New Radio connection establishment procedures, making it a critical component for service availability. The vulnerability's remote exploitability means that an attacker positioned within the network infrastructure or capable of intercepting network traffic could send the malformed message to trigger the system crash without requiring physical access or elevated privileges.
The operational impact of this vulnerability extends beyond simple service disruption to potentially affect network reliability and user experience across affected devices. When the modem crashes due to this improper input validation, it can result in complete loss of connectivity for the device, requiring manual intervention or device reboot to restore functionality. This type of denial of service attack could be particularly damaging in mission-critical applications where continuous connectivity is essential, such as emergency services, industrial automation, or transportation systems. The vulnerability's characteristics align with ATT&CK technique T1499.004, which covers network denial of service attacks, and demonstrates how weaknesses in input validation can create opportunities for attackers to compromise system availability.
Mitigation strategies for this vulnerability should focus on implementing robust input validation mechanisms within the modem's network processing stack, particularly for NR RRC Connection Setup messages. The patch MOLY01191612 addresses this issue by introducing enhanced validation routines that properly sanitize incoming connection setup parameters before processing, preventing malformed data from causing system crashes. Network administrators should prioritize applying this patch across all affected Modem NL1 devices and consider implementing network monitoring to detect unusual RRC message patterns that might indicate exploitation attempts. Additionally, organizations should establish baseline network security practices including traffic filtering and anomaly detection to identify potential exploitation attempts before they can cause service disruption, as this vulnerability demonstrates the importance of defensive programming practices in embedded systems.