CVE-2023-32843 in MT2735
Summary
by MITRE • 12/04/2023
In 5G Modem, there is a possible system crash due to improper error handling. This could lead to remote denial of service when receiving malformed RRC messages, with no additional execution privileges needed. User interaction is not needed for exploitation. Patch ID: MOLY01130204; Issue ID: MOLY01130204 (MSV-849).
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Analysis
by VulDB Data Team • 05/29/2025
The vulnerability identified as CVE-2023-32843 represents a critical flaw in 5G modem implementations that manifests through inadequate error handling mechanisms within the Radio Resource Control (RRC) protocol processing stack. This weakness exists at the foundational level of 5G network infrastructure where mobile devices communicate with base stations, creating a potential pathway for adversaries to disrupt service availability without requiring any privileged access or user interaction. The issue specifically affects the modem's ability to process malformed RRC messages that are part of the standard 5G communication protocol suite, indicating a fundamental breakdown in protocol validation and error recovery procedures.
The technical exploitation of this vulnerability occurs when a 5G modem receives specially crafted RRC messages that deviate from expected protocol specifications. These malformed messages trigger an improper error handling routine within the modem's software implementation, causing the system to enter an unstable state that ultimately results in a complete system crash. The vulnerability operates at the protocol processing layer where the modem interprets and responds to network control messages, making it particularly dangerous as it can affect the entire communication session and potentially impact network availability for legitimate users. This flaw demonstrates poor defensive programming practices where the system fails to implement proper input validation and graceful error recovery mechanisms, leading to abrupt termination of critical network services.
The operational impact of CVE-2023-32843 extends beyond simple service disruption to potentially compromise the reliability and integrity of 5G networks. Since no user interaction or elevated privileges are required for exploitation, attackers can remotely target affected modems through network-based attacks, making this vulnerability particularly concerning for network operators and device manufacturers. The remote attack vector means that malicious actors can systematically target deployed 5G infrastructure without physical access or user engagement, creating opportunities for large-scale denial of service attacks that could affect hundreds or thousands of devices simultaneously. This vulnerability directly impacts the availability aspect of the CIA triad and can be classified under CWE-707, which addresses improper error handling in software implementations.
Mitigation strategies for this vulnerability must focus on implementing robust error handling procedures and input validation mechanisms within the modem firmware. The patch MOLY01130204 specifically addresses this issue by enhancing the modem's RRC message processing to properly handle malformed inputs without causing system crashes. Organizations should prioritize firmware updates and ensure that all deployed 5G modems receive the appropriate patches as soon as possible. Network monitoring systems should be enhanced to detect anomalous RRC message patterns that might indicate attempted exploitation. From an ATT&CK framework perspective, this vulnerability maps to T1499.004 for network denial of service and T1595.001 for reconnaissance activities that could precede exploitation attempts. The vulnerability also highlights the importance of secure coding practices and adherence to industry standards such as ISO/IEC 15408 Common Criteria and NIST SP 800-63 for secure system design and implementation.