CVE-2023-32846 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: MOLY01128524; Issue ID: MOLY01138453 (MSV-861).
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 12/22/2023
The vulnerability identified as CVE-2023-32846 resides within 5G modem implementations and represents a critical weakness in error handling mechanisms that can result in system instability. This flaw specifically manifests when the modem receives malformed Radio Resource Control messages, which are essential components of 5G communication protocols responsible for managing radio resources between user equipment and network infrastructure. The improper error handling within the modem's processing logic creates a condition where the system becomes vulnerable to arbitrary code execution through carefully crafted malformed packets that trigger a system crash. The vulnerability's classification as a remote denial of service attack stems from the fact that adversaries can exploit this weakness without requiring any form of authentication or elevated privileges, making it particularly dangerous in networked environments where 5G modems are deployed. The absence of user interaction requirements for exploitation further amplifies the threat surface, as malicious actors can initiate attacks remotely without any direct engagement with the target device.
The technical root cause of this vulnerability lies in the inadequate validation and error management procedures implemented within the 5G modem's RRC message processing subsystem. When the modem encounters malformed RRC messages that do not conform to expected protocol specifications, the error handling mechanism fails to properly sanitize or reject these inputs, leading to memory corruption or stack overflow conditions that ultimately result in system termination. This type of vulnerability aligns with CWE-248, which addresses "Uncaught Exception" conditions where programs fail to handle exceptions properly, and can also be categorized under CWE-129, "Improper Validation of Array Index" if the error handling involves array access violations. The attack vector follows the ATT&CK framework's technique T1499.004 for "Endpoint Denial of Service" where adversaries target system resources to prevent legitimate use, and potentially T1595.001 for "Network Denial of Service" when the attack targets network infrastructure components.
The operational impact of CVE-2023-32846 extends beyond simple service disruption, as it can compromise the integrity of 5G network operations and potentially affect critical infrastructure systems that rely on these modems for connectivity. In mobile network environments, this vulnerability could lead to widespread service degradation or complete outages across multiple devices simultaneously, particularly affecting mission-critical applications such as emergency services, industrial automation, or financial transactions that depend on reliable 5G connectivity. The remote exploitation capability means that attackers can target multiple devices across different geographic locations without requiring physical access or network proximity, making it a significant concern for network operators who must maintain continuous service availability. The vulnerability's presence in modem firmware also means that patching may require coordinated efforts across multiple vendors and device manufacturers, potentially leading to extended periods of exposure while remediation efforts are underway.
The recommended mitigation strategies for this vulnerability encompass both immediate and long-term approaches to address the underlying issue. Immediate remediation involves applying the vendor-provided patch identified by Patch ID MOLY01128524, which specifically targets the error handling flaw in the RRC message processing logic. Network operators should prioritize deployment of this patch across all affected 5G modem implementations, particularly those serving critical infrastructure or high-availability environments. Additionally, implementing network-level monitoring and intrusion detection systems can help identify anomalous RRC message patterns that may indicate attempted exploitation of this vulnerability. The patch addresses the issue identified by Issue ID MOLY01138453 within the MSV-861 framework, which provides specific guidance on mitigating the error handling deficiencies. Organizations should also consider implementing network segmentation and access controls to limit the potential impact of successful exploitation attempts, while maintaining detailed logging of RRC message exchanges for forensic analysis purposes. Regular vulnerability assessments and penetration testing should be conducted to identify similar weaknesses in other components of the 5G infrastructure that may present analogous error handling vulnerabilities.