CVE-2026-48173 in Exynos 850
Summary
by MITRE • 11/05/2026
In the NAS message handler, improper validation of the length field in NAS message causes memory corruption
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 11/05/2026
The vulnerability resides within the Non-Access Stratum (NAS) protocol stack implementation, specifically affecting the message parsing and handling logic responsible for processing signaling data between user equipment and core network elements. The root cause is an insufficient input validation mechanism regarding the length field embedded in NAS messages. When a remote attacker or malicious actor crafts a specially constructed NAS packet with a manipulated length value that exceeds the actual buffer capacity allocated by the application, the system fails to perform adequate bounds checking before proceeding with memory operations. This oversight leads directly to heap-based buffer overflow conditions where data is written beyond the boundaries of the intended memory allocation.
From a technical perspective, this flaw aligns closely with CWE-120 Buffer Copy without Checking Size of Input and CWE-787 Out-of-bounds Write in the Common Weakness Enumeration taxonomy. The improper validation allows an attacker to control the amount of data written into adjacent memory regions, potentially overwriting critical program structures such as function pointers, exception handlers, or other metadata stored on the heap. In many modern operating systems and embedded environments utilizing ASLR (Address Space Layout Randomization) and DEP/NX (Data Execution Prevention), exploiting this vulnerability requires additional techniques to bypass these mitigations, but the fundamental memory corruption remains a severe security risk that can lead to arbitrary code execution if successfully exploited in conjunction with other weaknesses.
The operational impact of this vulnerability is significant as it compromises the integrity and availability of the network infrastructure handling NAS communications. Successful exploitation could allow an unauthenticated attacker to crash the service causing a denial of service condition, or more critically, execute malicious code within the context of the privileged process managing the connection. This level of access can facilitate further lateral movement within the network, interception of sensitive signaling data, or manipulation of subscriber profiles and session states. Given that NAS messages are fundamental to mobility management and session establishment in mobile networks like LTE and 5G NR, compromising this component undermines the trust model of the entire cellular architecture.
To mitigate this risk, developers must implement strict input validation routines that verify the length field against the maximum allowable size for the specific message type before any memory allocation or copy operation occurs. This includes enforcing upper bounds based on protocol specifications and ensuring that all buffer operations utilize safe functions that check array indices and lengths automatically. Additionally, deploying runtime protection mechanisms such as heap canaries, stack protectors, and advanced intrusion detection systems capable of identifying anomalous memory access patterns can help detect exploitation attempts in real time. Regular security audits focusing on the NAS message handler codebase are recommended to identify similar validation gaps across other protocol layers.
This vulnerability is categorized under ATT&CK technique T1203 Exploitation for Client Execution when considering the delivery vector through network signaling, and relates to CWE-78 Out-of-bounds Write which describes the specific memory corruption behavior observed during exploitation attempts targeting the NAS message handler component.