CVE-2026-35494 in Exynos 1280
Summary
by MITRE • 11/05/2026
In the baseband, memory corruption during NAS packet processing can cause a denial of service.
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Analysis
by VulDB Data Team • 11/05/2026
The vulnerability described involves a critical flaw within the Non-Access Stratum (NAS) protocol stack located in the cellular modem's baseband processor. The NAS layer is responsible for managing signaling connections between the User Equipment and the core network, handling functions such as registration, authentication, session management, and mobility procedures. During the processing of incoming or outgoing NAS packets, a memory corruption error occurs, which typically manifests as a buffer overflow, use-after-free condition, or heap corruption. This flaw is particularly severe because it resides in the baseband firmware, a component that operates independently from the main application processor and often runs with high privileges to ensure real-time communication reliability. The presence of such a defect indicates insufficient bounds checking or improper memory management practices during the parsing and handling of NAS message structures.
From an operational perspective, this vulnerability primarily results in a denial of service condition for the device's cellular connectivity. When the baseband processor encounters corrupted memory states due to malformed or specifically crafted NAS packets, it may trigger a watchdog reset, crash the modem firmware, or enter a fault state that requires a hard reboot to recover. This effectively renders the device unable to register with any mobile network, make calls, send SMS messages, or utilize data services until the system is restarted. While the immediate impact is limited to availability rather than confidentiality or integrity of user data on the application processor, it disrupts critical communication capabilities and can be exploited remotely by an attacker positioned within radio range who can inject malicious NAS signaling messages into the air interface.
This type of vulnerability aligns with CWE-120 Buffer Copy without Checking Size of Input and CWE-787 Out-of-bounds Write in terms of root cause, while the exploitation technique falls under ATT&CK T1499 Endpoint Denial of Service or potentially T1563 Remote Service Hijacking if it leads to a persistent state change. The attack vector is typically classified as Network-based with Local Privileges required on the radio interface, though in practice, physical proximity or compromised network infrastructure can facilitate remote exploitation without direct device access.
Mitigation strategies must focus on both immediate remediation and long-term architectural improvements. Vendors should prioritize deploying firmware patches that enforce strict input validation for all NAS packet fields, ensuring that buffer sizes are correctly calculated before any copy operations occur. Implementing memory protection mechanisms such as Stack Canaries or Address Space Layout Randomization within the baseband environment can help detect corruption attempts early. Furthermore, adopting a secure development lifecycle that includes rigorous fuzz testing of protocol parsers is essential to identify similar flaws in other network layers. For end-users and enterprise administrators, ensuring devices are updated with the latest security patches from manufacturers remains the most effective defense against this specific class of vulnerabilities until permanent architectural fixes are implemented by hardware vendors.