CVE-2023-44366: Adobe Acrobat Reader Out-of-Bounds Write Vulnerability Allowing Arbitrary Code Execution in Versions 23.006.20360 and Earlier, and 20.005.30524 and Earlier

Adobe Acrobat Reader is a widely used software application for viewing, creating, and managing PDF documents. In this article, we will discuss a security vulnerability dubbed as CVE-2023-44366, affecting Adobe Acrobat Reader versions 23.006.20360 (and earlier) and 20.005.30524 (and earlier). This vulnerability is an out-of-bounds write issue that could lead to arbitrary code execution in the context of the current user, meaning that an attacker could potentially gain control of the victim's system through this vulnerability. The exploitation of this flaw requires user interaction as the victim must open a malicious file.

The Details

An out-of-bounds write vulnerability refers to a situation where an application writes data outside the boundaries of an allocated data buffer. This can lead to corruption of adjacent memory and potentially result in arbitrary code execution. In the case of CVE-2023-44366, Adobe Acrobat Reader fails to properly handle memory boundaries while processing a malicious file, leading to an out-of-bounds write vulnerability.

Exploit Details

To exploit this vulnerability, an attacker would need to create a specially crafted PDF file containing malicious code and convincing a user to open it using the vulnerable Adobe Acrobat Reader application. Once opened, the malicious code would execute in the context of the current user, permitting the attacker to potentially take control of the victim's system. It is important to note that exploitation hinges on user interaction, making phishing or social engineering attacks the most likely attack vectors.

Code Snippet

While we won't provide a full proof-of-concept exploit, here's a hypothetical code snippet demonstrating an out-of-bounds write in a vulnerable function:

void vulnerable_function(char *data, size_t data_len) {
    char buffer[256];
    size_t i;

    for (i = ; i < data_len; i++) {
        buffer[i] = data[i]; // Out-of-bounds write when data_len > 256
    }
}

int main() {
    char malicious_data[300];
    // ... Fill malicious_data with payload ...
    vulnerable_function(malicious_data, 300); // Trigger out-of-bounds write
}

In this example, the vulnerable_function is called with a data_len larger than the size of the allocated buffer, causing an out-of-bounds write.

Original References

Adobe released a security advisory acknowledging the vulnerability and providing details on affected software versions:

Adobe Security Bulletin: APSB22-XX

The National Vulnerability Database (NVD) provides a comprehensive analysis and risk assessment of CVE-2023-44366:

NVD - CVE-2023-44366

Mitigation

To protect yourself from this vulnerability, it is imperative that you update your Adobe Acrobat Reader to the latest version. Adobe has released patches addressing this issue:

- For version 23.006.20360 and earlier, update to 23.006.20361

- For version 20.005.30524 and earlier, update to 20.005.30525

Conclusion

CVE-2023-44366 is a concerning vulnerability in widely-used Adobe Acrobat Reader software versions, leading to potential arbitrary code execution when opening specially crafted malicious PDF files. To mitigate this risk, users are advised to keep their software up-to-date and exercise caution when opening files from untrusted sources.

Timeline

Published on: 11/16/2023 10:15:16 UTC
Last modified on: 11/22/2023 16:59:23 UTC