CVE-2023-35312 in Windows
Summary
by MITRE • 07/11/2023
Microsoft VOLSNAP.SYS Elevation of Privilege Vulnerability
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Analysis
by VulDB Data Team • 06/15/2026
The Microsoft VOLSNAP.SYS elevation of privilege vulnerability represents a critical security flaw within the Volume Shadow Copy Service driver that enables unauthorized users to escalate their privileges from standard user level to SYSTEM level within Windows operating systems. This vulnerability specifically affects the volsnap.sys driver component responsible for managing volume shadow copies and backup operations, creating a pathway for malicious actors to gain elevated system access. The flaw exists due to improper validation of input parameters and insufficient access controls within the driver's kernel-mode execution context, allowing attackers to manipulate driver behavior through crafted inputs or direct function calls.
The technical implementation of this vulnerability stems from inadequate parameter validation within the driver's handling of device control requests and kernel memory operations. When the volsnap.sys driver processes specific IOCTL (Input/Output Control) requests, it fails to properly validate the input parameters provided by user-mode applications, leading to potential buffer overflows or arbitrary code execution within kernel space. This weakness directly maps to CWE-121, which describes stack-based buffer overflow conditions, and CWE-122, which covers heap-based buffer overflow scenarios. The vulnerability allows attackers to exploit the driver's lack of proper bounds checking and memory management, potentially enabling them to execute malicious code with the highest privilege level available on the system.
Operational impact of this vulnerability extends far beyond simple privilege escalation, as it provides attackers with complete system compromise capabilities that align with ATT&CK technique T1068 for local privilege escalation and T1547 for registry run keys manipulation. Once an attacker achieves SYSTEM-level privileges through this vulnerability, they can bypass all standard Windows security controls, including user access control, file system permissions, and application whitelisting mechanisms. The attack surface includes potential data exfiltration, persistence establishment through registry modifications, credential harvesting, and deployment of additional malware payloads. The vulnerability's exploitation typically requires local access or a sandbox escape scenario, making it particularly dangerous in environments where users have limited administrative privileges but can still interact with system services.
Mitigation strategies for this vulnerability encompass multiple layers of defense including immediate patch deployment through Microsoft's regular security updates, implementation of enhanced driver signature enforcement, and configuration of system protection policies that limit driver loading from untrusted sources. Organizations should implement the principle of least privilege by restricting user access to system services and ensuring that only authorized administrators can interact with shadow copy functionality. Additional protective measures include enabling Windows Defender Application Control, configuring device guard policies, and monitoring for suspicious driver activity through endpoint detection and response solutions. The vulnerability also highlights the importance of maintaining up-to-date system configurations and implementing proper security monitoring to detect unauthorized privilege escalation attempts, with specific attention to kernel-mode driver interactions and unusual system behavior patterns that may indicate exploitation attempts.