Overview
The CVE-2025-49683 is a severe vulnerability identified in the Virtual Hard Disk (VHDX) that allows an unauthorized attacker to execute code locally. This vulnerability primarily affects systems using VHDX for managing their virtual storage. The risk posed by this vulnerability is significant as it potentially enables a system compromise or data leakage, enabling an attacker to gain unauthorized control over the affected system or access sensitive information.
Vulnerability Summary
CVE ID: CVE-2025-49683
Severity: High (7.8 CVSS Score)
Attack Vector: Local
Privileges Required: None
User Interaction: None
Impact: System compromise, Data leakage
Affected Products
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Product | Affected Versions
Microsoft Windows | 10, Server 2016, Server 2019
Hyper-V | 2016, 2019
How the Exploit Works
The vulnerability exploits an integer overflow or wraparound in the VHDX. An integer overflow occurs when an arithmetic operation attempts to create a numeric value that is outside of the range that can be represented with a given number of bits. This may result in the value wrapping around to become a very small or negative number instead of the expected large positive number. This flaw in VHDX allows an attacker to craft malicious inputs that trigger the overflow, thereby leading to unexpected behavior in the system, including the execution of unauthorized code.
Conceptual Example Code
Consider a conceptual example of an application interacting with the vulnerable VHDX. The attacker could craft a malicious request exploiting the integer overflow vulnerability as follows:
# Attacker crafts a VHDX with a size parameter that when processed, would lead to integer overflow
create_vhdx --size=9223372036854775807 /path/to/malicious.vhdx
# Attacker then mounts the malicious VHDX, leading to overflow and potential unauthorized code execution
mount_vhdx /path/to/malicious.vhdxThis is a conceptual example and actual exploit code might differ significantly based on the environment, specific conditions, and the attacker’s intent.
Mitigation Guidance
The recommended mitigation approach for this vulnerability is to apply vendor-provided patches. If patches are not immediately available or cannot be applied at the moment, a temporary mitigation could involve the use of a Web Application Firewall (WAF) or Intrusion Detection System (IDS) to detect and block attempts to exploit this vulnerability.
Users and administrators are advised to stay updated with the latest security updates from the vendor and apply them as soon as they are available. Also, monitoring system logs and network traffic for any unusual activity can help detect any attempt to exploit this vulnerability. Regular audits of system and data access can also help in early detection and response.
