CVE-2026-21101 in Samsung
Summary
by MITRE • 09/09/2026
Improper input validation in DualDAR driver prior to SMR Sep-2026 Release 1 allows local privileged attackers to potentially execute arbitrary code with root privilege.
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Analysis
by VulDB Data Team • 09/09/2026
The vulnerability identified as an improper input validation flaw within the DualDAR driver represents a critical security risk for systems utilizing this specific kernel component, particularly those operating prior to the SMR September 2026 Release 1 update. This defect stems from insufficient sanitization and boundary checking of user-supplied or device-specific inputs before they are processed by the driver's core logic. In modern computing architectures, drivers operate at ring zero, granting them direct access to hardware resources and kernel memory spaces. When a driver fails to rigorously validate incoming data structures, it creates an avenue for local attackers who have already obtained privileged execution rights on the system to manipulate internal state variables or control flow mechanisms in unintended ways. The presence of this flaw indicates that the developer did not adequately enforce constraints on input length, type, or logical consistency during critical operations performed by the DualDAR driver.
From a technical perspective, improper input validation is classified under CWE-20: Improper Input Validation according to the Common Weakness Enumeration standard. This category encompasses scenarios where software receives data from an upstream component but fails to verify that the data meets expected specifications before processing it. In the context of kernel drivers, this often manifests as buffer overflows, integer overflows, or logic errors that allow for out-of-bounds memory access. An attacker leveraging this vulnerability would likely craft a malicious payload designed to exploit these unchecked boundaries. By sending specifically formatted requests through interfaces exposed by the DualDAR driver, such as IOCTLs or device file operations, the attacker can cause the kernel to execute arbitrary instructions in its context. This process typically involves overwriting return addresses on the stack or manipulating function pointers within data structures allocated by the driver, thereby hijacking the execution flow of the operating system.
The operational impact of this vulnerability is severe due to the privilege level required for exploitation and the resulting capabilities gained upon success. The description notes that local privileged attackers can potentially execute arbitrary code with root privileges. This implies a privilege escalation scenario where an attacker who already possesses administrative or high-level user access on the target machine can further elevate their rights to full system control, often referred to as root or SYSTEM level depending on the operating environment. Under the MITRE ATT&CK framework, this behavior aligns with T1068: Exploitation for Privilege Escalation and potentially T1055: Process Injection if the attacker utilizes memory manipulation techniques to inject code into legitimate system processes. Once root privileges are achieved, the attacker gains unrestricted access to all files on the system, can install persistent backdoors, disable security logging mechanisms, and pivot to attack other systems within the network with minimal resistance.
Mitigation strategies for this vulnerability primarily involve applying vendor-provided patches that address the input validation logic within the DualDAR driver codebase. Organizations must ensure they upgrade to SMR September 2026 Release 1 or any subsequent version where these checks have been implemented and tested. In environments where immediate patching is not feasible, defensive measures should include strict application whitelisting to prevent unauthorized execution of scripts or binaries that might serve as exploit vectors. Additionally, implementing kernel-level security modules such as SELinux or AppArmor can help restrict the actions a compromised process can perform, thereby limiting the blast radius even if an attacker successfully exploits this input validation flaw. Regular auditing of driver code and adherence to secure coding standards during development phases are essential preventive measures against similar vulnerabilities in future releases.