Adobe Acrobat Reader DC is widely known as a robust and reliable software for opening, viewing, and managing PDF documents. However, recent research has uncovered a critical vulnerability in the application that could expose users to potential exploits. The vulnerability, identified as CVE-2022-44516, affects Acrobat Reader DC versions 22.001.20085 (and earlier), 20.005.3031x (and earlier), and 17.012.30205 (and earlier).

Exploitation of this vulnerability can lead to a read past the end of an allocated memory structure.

- This exploit can be used by an attacker to bypass mitigations such as ASLR (Address Space Layout Randomization).

To execute this exploit, the victim needs to be tricked into opening a malicious file.

- Users are advised to update their Acrobat Reader DC software to the latest version to protect against this threat.

Vulnerability Details

An out-of-bounds read vulnerability exists in the affected versions of Acrobat Reader DC when parsing a specially crafted file. This vulnerability allows an attacker to read past the end of an allocated memory structure, potentially revealing sensitive data or enabling remote code execution. This exploit could be used by an attacker to bypass security mitigations such as ASLR, which is designed to prevent predictable target addresses for memory corruption vulnerabilities.

Exploit Example Code Snippet

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

int main(int argc, char* argv[]) {
  uint8_t *buffer, *ptr;
  size_t size;
  FILE *fd;

  // Read the crafted_file.pdf into a buffer
  fd = fopen("crafted_file.pdf", "rb");
  if (!fd) {
    fprintf(stderr, "Error opening file.\n");
    return 1;
  }

  fseek(fd, , SEEK_END);
  size = ftell(fd);
  fseek(fd, , SEEK_SET);

  buffer = (uint8_t*)malloc(size);
  if (!buffer) {
    fprintf(stderr, "Error allocating memory.\n");
    return 1;
  }

  fread(buffer, 1, size, fd);
  fclose(fd);

  // Simulate the vulnerable code
  ptr = buffer;
  while (ptr < buffer + size) {
    uint32_t length = *(uint32_t*)(ptr);
    ptr += 4;
    if ((ptr + length) > (buffer + size)) {
      fprintf(stderr, "Out-of-bounds read detected!\n");
      break;
    }

    // Reading past the end of the allocated memory structure
    ptr += length;
  }

  free(buffer);
  return ;
}

Original References

- Adobe Security Bulletin: APSB22-xx: Security update available for Acrobat Reader DC

Mitigation and Recommendations

1. Update Acrobat Reader DC: Users should immediately update their Acrobat Reader DC software to the most recent version to protect against this vulnerability. The newest version can be downloaded directly from Adobe's website.

2. Be cautious with file attachments: Users should always be wary of opening file attachments received via email, especially from unknown sources. Ensuring that other software on the user's system is up-to-date can further mitigate potential exploitation by cyber criminals.

3. Regularly monitor system and network logs: If attackers were to exploit this vulnerability, regular monitoring of system logs and network traffic would provide a better chance to detect any unusual behavior and take appropriate action.

Conclusion

The CVE-2022-44516 vulnerability poses a significant risk to users of older versions of Adobe Acrobat Reader DC. By updating to the latest version and practicing good security hygiene, users can protect themselves against potential exploitation. Prompt action to address known vulnerabilities is essential for maintaining a strong security posture and keeping sensitive information secure.

Timeline

Published on: 12/19/2024 00:15:05 UTC