CVE-2024-20004 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: MOLY01195812 (MSV-985).
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Analysis
by VulDB Data Team • 02/25/2024
The vulnerability identified as CVE-2024-20004 affects the Modem NL1 component and represents a critical denial of service weakness stemming from inadequate input validation mechanisms. This flaw exists within the network side of the modem's operation where it processes NR RRC Connection Setup messages from the network. The issue manifests when the modem receives malformed or invalid RRC connection setup messages that do not conform to expected protocol standards, leading to system instability and potential complete system crash. The vulnerability operates at the protocol handling layer where the modem's radio resource control functionality processes incoming network signals, making it particularly dangerous as it can be triggered through normal network communication without requiring any privileged access or user interaction.
The technical implementation of this vulnerability lies in the modem's insufficient validation of incoming NR RRC Connection Setup messages, which violates fundamental security principles of input sanitization and error handling. When processing these messages, the modem fails to properly validate message structure, field contents, or parameter ranges, allowing malformed data to propagate through the system's processing pipeline. This lack of proper validation creates a condition where malformed data can cause memory corruption, stack overflow, or other internal system errors that ultimately result in system crash or reboot. The vulnerability is classified under CWE-20 as "Improper Input Validation" and represents a classic example of how insufficient data validation can lead to system instability and denial of service conditions. The attack surface is particularly broad as it operates at the network interface level where all valid network traffic must pass through for processing.
The operational impact of this vulnerability extends beyond simple system downtime as it can affect network connectivity and service availability for users connected to networks utilizing affected Modem NL1 implementations. Remote attackers can exploit this vulnerability by simply transmitting specially crafted NR RRC Connection Setup messages to target devices, making it a particularly dangerous weakness for network infrastructure providers and mobile operators. The lack of requirement for additional execution privileges or user interaction significantly increases the attack surface and makes exploitation trivial for threat actors who can simply send malicious network traffic. This vulnerability directly maps to ATT&CK technique T1499.004 as "Endpoint Denial of Service" where adversaries can cause system unavailability through manipulation of network protocols. The potential for widespread disruption exists because this affects the core communication protocols used in 5G networks, making it particularly concerning for operators maintaining large network deployments.
Mitigation strategies for CVE-2024-20004 should focus on implementing robust input validation mechanisms within the modem's network processing components and applying the vendor-provided patch MOLY01191612. Network administrators should consider implementing network-level filtering to detect and block malformed RRC connection setup messages, although this approach may not be comprehensive given the sophisticated nature of the attack vectors. The patch addresses the root cause by strengthening input validation routines and improving error handling within the modem's NR RRC processing module. Additionally, operators should implement monitoring systems to detect unusual system crash patterns or network traffic anomalies that might indicate exploitation attempts. System hardening measures including regular firmware updates, network segmentation, and implementing redundant communication paths can help minimize the impact of potential exploitation. Organizations should also consider implementing intrusion detection systems that can identify and alert on suspicious RRC protocol behavior patterns, as this vulnerability represents a significant risk to 5G network reliability and service continuity.