CVE-2023-33015 in 15 5G IoT Modem
Summary
by MITRE • 09/05/2023
Transient DOS in WLAN Firmware while interpreting MBSSID IE of a received beacon frame.
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Analysis
by VulDB Data Team • 09/05/2023
This vulnerability represents a transient denial of service condition within wireless local area network firmware that occurs during the interpretation of a multiple basic service set identifier information element within received beacon frames. The flaw manifests when the wireless access point or client device processes malformed or specially crafted multiple bssid information elements that contain unexpected data structures or invalid field values. The issue stems from insufficient input validation and parsing routines within the firmware's management frame processing subsystem, where the device attempts to interpret the mbssid ie without proper bounds checking or error handling mechanisms. This vulnerability specifically affects the beacon frame processing logic which is critical for maintaining network connectivity and proper wireless device association behavior.
The technical implementation of this flaw involves the firmware's failure to properly validate the length field within the multiple bssid information element structure before attempting to parse subsequent data segments. When a maliciously crafted beacon frame containing an oversized or malformed mbssid ie is transmitted within range of the vulnerable device, the firmware's parser attempts to process the invalid data without proper safeguards, leading to memory corruption or execution flow disruption. The vulnerability can be triggered through various means including crafting specific beacon frames with manipulated information element lengths, improper padding bytes, or invalid bssid list entries that exceed expected boundaries. This type of vulnerability typically maps to CWE-129 Input Validation and Output Encoding as it involves improper validation of input data from external sources, and may also align with CWE-787 Out-of-bounds Write when memory corruption occurs due to buffer overflows during parsing operations.
The operational impact of this transient denial of service condition can severely disrupt wireless network operations by causing individual access points or client devices to become unresponsive or restart their wireless services. Affected devices may experience complete loss of wireless connectivity until manual intervention or automatic recovery mechanisms are triggered, potentially affecting multiple users within the impacted network segment. The vulnerability is particularly concerning in enterprise environments where wireless infrastructure reliability is critical for business operations, as it can cause cascading failures when multiple access points become unresponsive simultaneously due to a single malicious beacon frame. Network administrators may observe intermittent disconnections, failed associations, or complete wireless service outages while the vulnerable device attempts to process the malformed information element and recovers from the resulting system instability.
Mitigation strategies for this vulnerability should focus on firmware updates provided by vendors that include proper input validation routines and bounds checking for all information elements within beacon frames. Network administrators should implement monitoring solutions to detect anomalous beacon frame patterns and consider deploying wireless intrusion detection systems that can identify and block malformed management frames before they reach vulnerable devices. The implementation of proper rate limiting or frame filtering mechanisms at the wireless access point level can help prevent malicious beacon frames from overwhelming device processing capabilities. Additionally, organizations should ensure that wireless firmware is regularly updated with security patches and maintain inventory tracking of all wireless devices to quickly identify and remediate affected systems. This vulnerability aligns with several attack techniques documented in the mitre att&ck framework including initial access through wireless network reconnaissance and privilege escalation through service disruption attacks, making it important for organizations to implement comprehensive wireless security monitoring and incident response procedures.