CVE-2025-53723 in Windows
Summary
by MITRE • 08/12/2025
Numeric truncation error in Windows Hyper-V allows an authorized attacker to elevate privileges locally.
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Analysis
by VulDB Data Team • 11/22/2025
The vulnerability identified as CVE-2025-53723 represents a critical numeric truncation error within the Windows Hyper-V hypervisor implementation that enables local privilege escalation for authorized attackers. This flaw exists in the hypervisor's handling of numeric values during memory management and virtual machine operations, specifically affecting the way unsigned integers are processed when transitioning between different privilege levels. The vulnerability stems from improper validation of numeric boundaries within the Hyper-V kernel components, creating a scenario where an attacker with legitimate access to a system can exploit this weakness to gain elevated privileges. Such numeric truncation errors typically occur when data types with different bit widths are improperly converted, leading to unexpected behavior in security-critical code paths. The issue is particularly concerning because it affects the foundational hypervisor layer that manages virtual machine execution and resource allocation, making it a prime target for attackers seeking to establish persistent elevated access within virtualized environments.
The technical implementation of this vulnerability involves the hypervisor's memory management subsystem where unsigned integer values are truncated during operations that should maintain their full precision. When processing virtual machine memory mappings or hardware resource allocations, the system performs calculations that involve numeric values exceeding the capacity of their designated data types. This truncation results in loss of significant bits and can cause the hypervisor to make incorrect decisions regarding memory access controls or privilege boundaries. The flaw manifests when an attacker can influence the numeric values used in these calculations through legitimate system interfaces, such as virtual machine configuration parameters or memory allocation requests. The vulnerability is classified under CWE-190 as an integer overflow or wraparound, specifically involving unsigned integer truncation during arithmetic operations. The attack vector requires local system access and leverages the legitimate administrative privileges that users might possess to execute malicious code that manipulates the numeric values, causing the hypervisor to grant elevated permissions through the truncated arithmetic operations.
The operational impact of CVE-2025-53723 extends beyond simple privilege escalation, potentially enabling attackers to compromise entire virtualized infrastructures and establish persistent backdoors within cloud or enterprise environments. Organizations utilizing Hyper-V virtualization platforms face significant risk as this vulnerability can be exploited to bypass standard security controls and access sensitive virtual machines or host systems. The vulnerability affects systems running Windows Server versions that include Hyper-V functionality, particularly those configured with multiple virtual machines or complex virtualization topologies. Attackers can exploit this weakness to gain SYSTEM-level privileges on the host system, potentially allowing them to manipulate or extract data from other virtual machines running on the same physical host. This creates a serious threat to multi-tenant cloud environments where isolation between virtual machines is compromised, and can lead to data breaches, service disruption, and unauthorized access to confidential information. The vulnerability's impact is amplified in environments where Hyper-V is used for containerization or as part of larger virtualization infrastructures, as it provides a pathway for attackers to move laterally within the virtualized environment.
Mitigation strategies for CVE-2025-53723 should focus on immediate patch deployment from Microsoft, while implementing additional monitoring and access controls to detect potential exploitation attempts. Organizations must prioritize updating their Hyper-V environments with the latest security patches and ensuring all virtual machines are running patched operating systems. Network segmentation and principle of least privilege should be enforced to limit the potential impact of successful exploitation, particularly for virtual machines that might be running with elevated privileges. Security monitoring should include detection of unusual memory allocation patterns, privilege escalation attempts, and suspicious virtual machine configuration changes that could indicate exploitation of the numeric truncation vulnerability. System administrators should implement enhanced logging for Hyper-V operations and monitor for anomalous behavior in virtual machine memory management. The ATT&CK framework categorizes this vulnerability under privilege escalation techniques, specifically targeting T1068 which involves exploiting vulnerabilities to gain elevated privileges. Organizations should also consider implementing micro-segmentation strategies for virtualized environments and maintain detailed inventory of all virtual machines and their respective privilege levels to quickly identify any unauthorized access or privilege changes that might result from exploitation of this vulnerability.