Critical Heap Overflow in Microsoft RD Gateway (CVE-2025-29967): Remote Code Execution Risk
Introduction
Remote Desktop Gateway Services are critical for secure remote access, but a newly discovered vulnerability, CVE-2025-29967, threatens to compromise these systems severely. This heap-based buffer overflow vulnerability allows attackers to execute arbitrary code remotely without authentication, posing a significant risk to enterprise security.
Affected Systems and Versions
- Microsoft Remote Desktop Gateway Service on Windows Server (specific versions not disclosed by vendor advisory)
- Microsoft Remote Desktop Clients (specific versions not disclosed by vendor advisory)
Technical Information
CVE-2025-29967 is classified as a heap-based buffer overflow (CWE-122). The vulnerability arises from improper handling of specially crafted network packets sent to the Remote Desktop Gateway Service. Attackers can exploit this flaw remotely without authentication, potentially gaining SYSTEM-level privileges and executing arbitrary code.
Attack Vectors
- Network-based: Exploitation requires no authentication, making internet-exposed RD Gateway instances particularly vulnerable.
- Payload Delivery: Malicious packets can be directly sent over the network to trigger the overflow.
Patch Information
Microsoft has addressed CVE-2025-29967 in its May 2025 security updates. Organizations should apply these patches immediately via Windows Update or enterprise management tools like WSUS or Intune.
Alternative Mitigations
- Restrict RD Gateway access to trusted IP addresses.
- Enable Network Level Authentication (NLA).
- Disable RD Gateway if not required.
Detection Methods
- Monitor Windows Remote Desktop Services logs (Event ID 1149) for unusual connection attempts.
- Implement IDS/IPS rules to detect exploitation attempts targeting RD Gateway.
Vendor Security History
Microsoft has previously addressed critical vulnerabilities in Remote Desktop Services, such as BlueKeep (CVE-2019-0708) and DejaBlue (CVE-2019-1182), which were actively exploited in the wild. The vendor typically responds promptly, releasing patches during monthly Patch Tuesday updates.
References
Given the critical nature of CVE-2025-29967, immediate action is essential to secure affected systems and prevent potential exploitation.
