CVE-2025-48817 Overview
CVE-2025-48817 is a relative path traversal vulnerability in the Microsoft Remote Desktop Client that enables an unauthorized attacker to execute arbitrary code over a network. This vulnerability affects the Remote Desktop Client application across a wide range of Windows operating systems, including Windows 10, Windows 11, and multiple Windows Server versions. The vulnerability is classified under CWE-23 (Relative Path Traversal), indicating that the affected component fails to properly sanitize user-supplied path input, allowing attackers to traverse directory structures and potentially write or execute malicious files outside of intended directories.
Critical Impact
Successful exploitation allows remote attackers to achieve code execution on vulnerable systems by manipulating file paths during Remote Desktop connections, potentially leading to full system compromise.
Affected Products
- Microsoft Remote Desktop Client (Windows)
- Microsoft Windows App (Windows)
- Microsoft Windows 10 (versions 1507, 1607, 1809, 21H2, 22H2)
- Microsoft Windows 11 (versions 22H2, 23H2, 24H2)
- Microsoft Windows Server 2008, 2012, 2016, 2019, 2022, 2022 23H2, 2025
Discovery Timeline
- 2025-07-08 - CVE-2025-48817 published to NVD
- 2025-07-15 - Last updated in NVD database
Technical Details for CVE-2025-48817
Vulnerability Analysis
This vulnerability exists in the Microsoft Remote Desktop Client's file path handling mechanism. When processing certain operations during an RDP session, the client fails to adequately validate and sanitize path components, allowing relative path traversal sequences such as ../ to be processed. An attacker can exploit this weakness to escape the intended directory context and access or write files to arbitrary locations on the victim's filesystem.
The attack requires user interaction, as the victim must connect to a malicious RDP server or be induced to open a crafted RDP file. Once the connection is established, the attacker-controlled server can send specially crafted responses that exploit the path traversal flaw. This can result in the execution of attacker-supplied code with the privileges of the user running the Remote Desktop Client.
The impact of successful exploitation is significant, as it can lead to complete compromise of confidentiality, integrity, and availability on the affected system. Given the widespread deployment of Remote Desktop services in enterprise environments, this vulnerability poses a substantial risk to organizational security.
Root Cause
The root cause of CVE-2025-48817 lies in improper input validation within the Remote Desktop Client's file handling routines. Specifically, the application does not properly neutralize special path elements (such as .. sequences) before using the path in file operations. This allows an attacker to construct path strings that traverse outside the expected directory hierarchy.
The vulnerability is categorized as CWE-23 (Relative Path Traversal), which occurs when software uses external input to construct a pathname that should be within a restricted directory, but does not properly neutralize sequences such as .. that can resolve to a location outside of that directory.
Attack Vector
The attack is network-based and requires user interaction. A typical exploitation scenario involves:
- An attacker sets up a malicious RDP server or compromises an existing RDP server
- The victim is social-engineered into connecting to the malicious server (e.g., via a phishing email containing a .rdp file)
- During the RDP session, the malicious server sends specially crafted responses containing path traversal sequences
- The vulnerable Remote Desktop Client processes these paths without proper sanitization
- The attacker can write malicious files to arbitrary locations or execute code on the victim's system
The vulnerability affects remote desktop client connections, meaning that the network attack vector combined with user interaction makes this exploitable in scenarios where users connect to untrusted or compromised RDP endpoints.
Detection Methods for CVE-2025-48817
Indicators of Compromise
- Unusual Remote Desktop Client behavior, including unexpected file creation or modification in system directories
- RDP connection logs showing connections to unknown or suspicious external servers
- File system artifacts containing path traversal sequences (../, ..\\) in file paths associated with RDP operations
- Unexpected executable files appearing in user profile directories or system paths after RDP sessions
Detection Strategies
- Monitor file system activity during and immediately after Remote Desktop sessions for writes to sensitive directories
- Implement network traffic analysis to detect RDP connections to unauthorized or suspicious servers
- Deploy endpoint detection rules that alert on path traversal patterns in file operations initiated by mstsc.exe or related RDP processes
- Review RDP configuration files (.rdp) for malicious or unexpected server targets before execution
Monitoring Recommendations
- Enable and centralize Windows Event Logs related to Remote Desktop connections (Event IDs 1024, 1025, 1149 in Microsoft-Windows-TerminalServices-RDPClient logs)
- Implement file integrity monitoring on critical system directories to detect unauthorized modifications
- Configure SentinelOne behavioral AI to detect anomalous file operations originating from Remote Desktop Client processes
How to Mitigate CVE-2025-48817
Immediate Actions Required
- Apply the security patches released by Microsoft immediately across all affected systems
- Restrict Remote Desktop Client usage to trusted, known RDP servers only
- Educate users about the risks of connecting to untrusted RDP servers or opening .rdp files from unknown sources
- Consider disabling Remote Desktop Client functionality for users who do not require it
Patch Information
Microsoft has released security updates to address this vulnerability. Organizations should apply the patches available through the Microsoft Security Update Guide for CVE-2025-48817. The updates are available through Windows Update, Windows Server Update Services (WSUS), and the Microsoft Update Catalog.
Ensure that all affected products are updated, including:
- Microsoft Remote Desktop Client
- Microsoft Windows App
- All supported versions of Windows 10, Windows 11, and Windows Server
Workarounds
- Block outbound RDP connections to untrusted networks at the firewall level until patches are applied
- Use Group Policy to restrict which RDP servers users can connect to via Remote Desktop Gateway
- Disable automatic file redirection and clipboard sharing in RDP client settings to reduce attack surface
- Implement network segmentation to limit exposure of systems running vulnerable Remote Desktop Clients
# Group Policy setting to restrict RDP connections
# Navigate to: Computer Configuration > Administrative Templates > Windows Components > Remote Desktop Services > Remote Desktop Connection Client
# Enable: "Specify SHA1 thumbprints of certificates representing trusted .rdp publishers"
# This helps ensure users only connect to authorized RDP servers
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
