In today's digital world, Portable Document Format (PDF) has become an essential tool for sharing and distributing documents, especially in the business environment. Consequently, the security of PDF files and the software we use for reading and editing them is of paramount importance. In this long-read post, we will discuss a recently discovered security vulnerability in Foxit PDF Reader and PDF Editor (CVE-2022-47881), which could have potential implications for users if exploited by an attacker.

CVE-2022-47881 – Vulnerability Details

Foxit PDF Reader and PDF Editor software versions 11.2.1.53537 and earlier contain an Out-of-Bounds (OOB) Read vulnerability. An OOB Read vulnerability arises when a software reads data past the end, or before the beginning of an intended buffer, resulting in information disclosure or application crash.

This security vulnerability has been officially documented in the CVE reference database under the Common Vulnerabilities and Exposures (CVE) ID: CVE-2022-47881. The National Vulnerability Database (NVD) has assigned it a CVSS v3 base score of 7.5, indicating a high level of severity.

How the Vulnerability Works

An attacker could exploit this vulnerability by crafting a malicious PDF file that, when opened by a user in a vulnerable version of Foxit PDF Reader or PDF Editor, would trigger an OOB Read operation, leading to information disclosure or application crash.

The vulnerability exists due to improper input validation in the software's handling of certain PDF file elements. The following code snippet demonstrates this issue:

obj_1 = getObjectByID(obj_id);
if (obj_1 != nullptr)
{
  int obj_length = obj_1->getLength();
  int read_offset = /* Offset value from the malicious PDF */;
  
  // The software improperly reads data beyond the intended buffer,
  // leading to an Out-of-Bounds Read vulnerability
  readData(obj_1, read_offset, obj_length);
}

By manipulating the read_offset value in the malicious PDF, an attacker could trigger an OOB Read operation, leading to unintended consequences such as information disclosure or application crashes.

Exploiting the Vulnerability

To exploit this vulnerability, an attacker needs to craft a malicious PDF file and then send it to their target victims. Should the victim open the malicious PDF with an affected version of Foxit PDF Reader or PDF Editor, the attacker could potentially access sensitive information, depending on the system's memory layout, or cause the application to crash, disrupting the victim's workflow.

Mitigations

Foxit Software has released a security update that addresses this vulnerability. Users are strongly recommended to update their Foxit PDF Reader and PDF Editor installations to version 11.3. or later. You can download the latest version from the Foxit Software website.

For users who cannot immediately update to the latest version, the following precautions should be taken:

Regularly back up important data to minimize the impact of potential data loss.

3. Utilize security software, such as antivirus and firewall, to actively monitor and protect your system from potential threats.

Conclusion

The discovery of the CVE-2022-47881 vulnerability in Foxit PDF Reader and PDF Editor serves as a reminder to stay vigilant and ensure that the software we use daily is up-to-date and secure. By doing so, we can safeguard our systems and data against potential threats and malicious attacks.

Timeline

Published on: 01/18/2023 15:15:00 UTC
Last modified on: 01/25/2023 20:15:00 UTC