CVE-2023-21586: Critical NULL Pointer Dereference Vulnerability in Adobe Acrobat Reader Leads to Application Denial-of-Service (DoS)

Adobe Acrobat Reader, a widely used application for viewing and processing PDF files, is affected by a critical vulnerability in versions 22.003.20282 (and earlier), 22.003.20281 (and earlier), and 20.005.30418 (and earlier). The vulnerability, identified as CVE-2023-21586, is a NULL Pointer Dereference flaw that could be exploited by an unauthenticated attacker to cause an application denial-of-service (DoS) in the context of the current user. The successful exploitation of this issue requires user interaction, such as opening a malicious file.

In this post, we'll delve into the details of CVE-2023-21586, including code snippets, original references, and exploit details. Stay tuned to learn how to protect your systems from this critical vulnerability.

Code Snippet

A NULL Pointer Dereference occurs when an application reads or writes data to a memory address with a value of "NULL." This can result in crashes, data corruption, and in some cases, code execution. In the case of CVE-2023-21586, an improperly handled object in the affected Adobe Acrobat Reader versions may cause a NULL Pointer Dereference.

Here's an example of a vulnerable code snippet that could lead to a NULL Pointer Dereference

/* Suppose obj is an object from Adobe Acrobat Reader's internal structure */

void process_obj(object* obj) {
    if (obj == NULL) {
        // This could lead to a NULL Pointer Dereference vulnerability
        // when attempting to access obj->data
    }

    print(obj->data);
}

Original References

Adobe has acknowledged the existence of CVE-2023-21586 in its Security Bulletin APSB22-XX, released on [DATE]. By exploiting this vulnerability, an attacker could trigger a crash and deny access to the application.

For more information about the affected versions, exploit scenarios, and remedies, please consult the following original references:

1. Adobe Security Bulletin APSB22-XX
2. CVE-2023-21586 - NIST National Vulnerability Database (NVD)

Exploit Details

The exploitation of CVE-2023-21586 involves crafting a malicious PDF file containing a specific object that triggers the NULL Pointer Dereference. The attacker must then convince the victim to open the malicious file using a vulnerable version of Adobe Acrobat Reader. Once the file is opened, the application crashes, rendering it inoperable and causing a denial-of-service condition.

To protect yourself from this type of attack, it is essential to keep your Adobe Acrobat Reader version up-to-date and avoid opening files from untrusted sources.

Conclusion

CVE-2023-21586 is a critical vulnerability affecting Adobe Acrobat Reader versions 22.003.20282 (and earlier), 22.003.20281 (and earlier), and 20.005.30418 (and earlier). This NULL Pointer Dereference flaw could allow an unauthenticated attacker to crash the application, leading to a denial-of-service condition.

To mitigate the risk, users should update to the latest available version of Adobe Acrobat Reader and exercise caution when opening files from unknown sources. Additionally, staying informed about the latest security advisories and vulnerabilities within the software you use is crucial to maintaining a secure environment.

Timeline

Published on: 12/18/2024 23:32:03 UTC