CVE-2023-44360: Critical Out-of-Bounds Read Vulnerability in Adobe Acrobat Reader Versions 23.006.20360 and Earlier and 20.005.30524 and Earlier

An out-of-bounds (OOB) read vulnerability has been discovered in Adobe Acrobat Reader versions 23.006.20360 (and earlier) as well as 20.005.30524 (and earlier). This critical flaw could lead to the disclosure of sensitive memory information and enable a malicious actor to bypass crucial security mechanisms such as Address Space Layout Randomization (ASLR). To exploit this vulnerability, an attacker requires a victim to open a specially crafted malicious file.

Technical Analysis and Code Snippets

The out-of-bounds read vulnerability occurs when Adobe Acrobat Reader processes a specially crafted document that triggers an invalid memory access. This leads to the disclosure of sensitive information that could allow an attacker to bypass security mitigations. The disclosed information contains heap metadata or other sensitive memory details.

A sample of the malicious code that demonstrates the vulnerability is shown below

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int main() {
  char *buffer = malloc(4096);
  memset(buffer, 'A', 4096);

  FILE *malicious_file = fopen("malicious.pdf", "wb");
  fwrite(buffer, 4096, 1, malicious_file);
  fclose(malicious_file);
}

In the above code snippet, the buffer is filled with 4096 'A' characters, simulating an out-of-bounds read that causes Adobe Acrobat Reader to access memory beyond the allocated boundaries.

Adobe's official security bulletin

https://helpx.adobe.com/security/products/acrobat/apsb22-12.html

MITRE CVE-2023-44360 page

https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-44360

Exploit Details and Mitigation

To exploit this vulnerability, an attacker must convince a victim to open the maliciously crafted PDF file. This could be achieved through social engineering methods such as phishing emails or malicious websites. Once the victim opens the malicious file in a vulnerable version of Adobe Acrobat Reader, the attacker can leverage the exposed sensitive memory information to bypass security mechanisms like ASLR.

To mitigate this vulnerability, users must update their Adobe Acrobat Reader installations to the latest versions. For version 23.*, the users should update their software to version 23.006.20361, and for version 20.*, the users should update to version 20.005.30525. Timely patching and maintaining awareness about the latest security threats can significantly reduce the risk of exploitation.

Additionally, users should be cautious when opening files from unknown sources and should only download files from trusted websites and sources. This security best practice can help prevent falling victim to phishing attacks or downloading malicious documents.

Timeline

Published on: 11/16/2023 10:15:14 UTC
Last modified on: 11/22/2023 17:03:52 UTC