A high-severity use-after-free vulnerability has been identified in Foxit PDF Reader, which could allow an attacker to execute arbitrary code on a user's system. Successful exploitation occurs when a user opens a specially crafted, malicious PDF file, potentially leading to a full system compromise. Organizations should prioritize applying the vendor-provided security updates to mitigate this significant risk.

This is a use-after-free (UAF) memory corruption vulnerability. The vulnerability is triggered when the software's PDF parsing engine processes a specially crafted PDF file. The application incorrectly continues to use a pointer to a memory location after that memory has been freed (deallocated). An attacker can exploit this by crafting a PDF file that causes the application to free a specific memory object and then reallocates that same memory space with malicious shellcode. When the application later attempts to use the original, now-invalid pointer, it will instead access the attacker's malicious code, leading to arbitrary code execution in the context of the current user.

This vulnerability is rated as High severity with a CVSS score of 7.8. Successful exploitation could have a significant negative impact on the organization. An attacker who convinces a user to open a malicious PDF file could execute arbitrary code with the same privileges as that user. This could lead to the installation of malware such as ransomware or spyware, the theft of sensitive corporate or personal data, loss of system integrity, and could allow the attacker to establish a persistent foothold in the network, leading to further lateral movement and compromise.

Immediate Action: Apply vendor security updates immediately to all systems running vulnerable versions of Foxit PDF Reader. The vendor has released patches to address this vulnerability. After patching, monitor for any signs of exploitation attempts by reviewing application and security logs for unusual activity related to the PDF reader process.

Proactive Monitoring: Implement enhanced monitoring for systems where Foxit PDF Reader is installed. Security teams should look for signs of compromise, including:

• Unexpected application crashes of the PDF reader process in system event logs.
• The PDF reader process (e.g., FoxitPDFReader.exe) spawning child processes such as cmd.exe, powershell.exe, or other unexpected executables.
• Unusual outbound network traffic originating from workstations, particularly from the PDF reader process, to unknown or suspicious IP addresses.

Compensating Controls: If immediate patching is not feasible, the following compensating controls can help reduce the risk:

• Enforce a policy of only opening PDF documents from trusted and verified sources.
• Utilize application control solutions (e.g., AppLocker) to prevent the PDF reader from launching other applications.
• Configure Attack Surface Reduction (ASR) rules to block office applications from creating executable content or child processes.
• Train users to be suspicious of unsolicited email attachments and to report any unusual application behavior.

Public Exploit Available: false

Given the high severity (CVSS 7.8) of this vulnerability and its potential for arbitrary code execution via a common file type, we strongly recommend that organizations prioritize the immediate deployment of the vendor-supplied security updates. Although this CVE is not currently listed on the CISA KEV catalog, its client-side nature makes it a prime candidate for phishing campaigns. All workstations with Foxit PDF Reader installed should be considered at risk and patched without delay to prevent potential system compromise and data breaches.