CVE-2025-26639 in Windows
Summary
by MITRE • 04/08/2025
Integer overflow or wraparound in Windows USB Print Driver allows an authorized attacker to elevate privileges locally.
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Analysis
by VulDB Data Team • 07/03/2025
The vulnerability identified as CVE-2025-26639 represents a critical integer overflow condition within the Windows USB Print Driver component that enables local privilege escalation for authenticated attackers. This flaw exists in the driver's handling of integer values during print job processing operations, specifically when managing buffer sizes or data lengths associated with USB communication protocols. The vulnerability stems from inadequate input validation and arithmetic overflow protection mechanisms within the kernel-mode driver code that processes print requests through USB interfaces.
The technical implementation of this vulnerability involves a scenario where the USB Print Driver performs arithmetic operations on integer variables that can exceed their maximum representable values, causing wraparound behavior that results in unexpected memory access patterns. When an authenticated user submits a print job with specially crafted parameters, the driver fails to properly validate integer inputs before performing calculations that determine buffer allocation sizes or data transfer limits. This condition creates a situation where the integer overflow can lead to memory corruption, potentially allowing an attacker to manipulate memory layout and execute arbitrary code with elevated privileges.
From an operational perspective, this vulnerability presents a significant risk to Windows environments as it requires only local authentication to exploit, eliminating the need for network access or complex attack vectors. The attack surface is particularly concerning given the widespread use of USB printing capabilities across enterprise networks and the typical administrative privileges associated with print driver installations. An attacker with low-privilege user access can leverage this vulnerability to gain SYSTEM-level privileges, potentially enabling full system compromise through subsequent lateral movement or persistence mechanisms. The impact extends beyond simple privilege escalation as it can facilitate data exfiltration, system modification, or establishment of persistent backdoors.
Security professionals should implement immediate mitigations including disabling unnecessary USB printing capabilities, applying Microsoft security patches upon release, and monitoring for suspicious print job activity that might indicate exploitation attempts. The vulnerability aligns with CWE-190, Integer Overflow or Wraparound, and maps to ATT&CK technique T1068, Exploitation for Privilege Escalation, within the privilege escalation category. Organizations should also consider implementing application whitelisting policies for print drivers, restricting USB device access through group policies, and conducting regular security assessments of print server configurations. The remediation approach must include comprehensive testing of updated drivers to ensure compatibility while addressing the underlying integer validation issues that enable this class of vulnerability.