CVE-2023-33099 in Snapdragon
Summary
by MITRE • 04/01/2024
Transient DOS while processing SMS container of non-standard size received in DL NAS transport in NR.
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Analysis
by VulDB Data Team • 01/13/2025
This vulnerability exists within the 5G New Radio (NR) network infrastructure where the system fails to properly handle SMS container messages of non-standard size received through the DL NAS transport layer. The issue manifests as a transient denial of service condition that occurs during the processing of these malformed SMS containers, creating temporary network disruption for affected subscribers. The vulnerability specifically impacts the handling of downlink NAS (Non-Access Stratum) transport messages in 5G networks, where the system attempts to parse and process SMS data but encounters unexpected container sizing that causes temporary system instability. This represents a critical weakness in the network's message processing logic that can be exploited to temporarily disrupt service for users within the affected network segments.
The technical flaw stems from inadequate input validation and error handling within the NAS message processing component of the 5G core network. When the system receives an SMS container with dimensions that deviate from expected standards, the processing routine fails to properly validate the container size before attempting to parse its contents. This leads to a temporary system crash or hang state during message processing, effectively removing the affected subscriber from the network service for a brief period. The vulnerability is classified as a transient denial of service because the system recovers automatically once the processing error is encountered, but the temporary disruption causes service interruption. According to CWE standards, this maps to CWE-129 Input Validation and Output Encoding, specifically involving improper handling of input data that exceeds expected boundaries. The flaw also aligns with ATT&CK technique T1499.004 for Denial of Service by Resource Exhaustion, where the system temporarily becomes unavailable due to processing errors.
The operational impact of this vulnerability extends beyond simple service disruption to potentially affect network reliability and user experience in 5G environments. Network operators may experience temporary degradation of service for subscribers within affected areas, particularly during peak usage times when multiple users might simultaneously encounter this issue. The transient nature of the problem means that network monitoring systems may not immediately identify the root cause, leading to extended troubleshooting periods and potential customer service issues. This vulnerability affects the integrity of 5G network operations and could potentially be exploited by attackers to create service degradation patterns that might mask other security issues. The impact is particularly concerning for mission-critical applications that depend on 5G connectivity, as temporary service interruptions could have cascading effects on dependent systems and services.
Mitigation strategies should focus on implementing robust input validation and error handling mechanisms within the NAS processing components of 5G networks. Network operators should deploy firmware updates that include enhanced validation routines for SMS container sizes and implement rate limiting mechanisms to prevent exploitation through repeated malformed message attempts. System monitoring should be enhanced to detect unusual processing patterns that might indicate this vulnerability being exploited. Regular security assessments of 5G core network components should be conducted to identify similar validation flaws in other message processing pathways. Additionally, implementing network segmentation and isolation techniques can limit the scope of potential disruptions while allowing affected systems to recover. The solution should also include automated recovery mechanisms that can quickly restore service when transient conditions occur, reducing the impact on end users and maintaining overall network resilience.