CVE-2022-28671 in Foxit
Summary
by MITRE • 07/18/2022
This vulnerability allows remote attackers to execute arbitrary code on affected installations of Foxit PDF Reader 11.2.1.53537. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file. The specific flaw exists within the handling of Doc objects. The issue results from the lack of validating the existence of an object prior to performing operations on the object. An attacker can leverage this vulnerability to execute code in the context of the current process. Was ZDI-CAN-16639.
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Analysis
by VulDB Data Team • 08/06/2022
CVE-2022-28671 represents a critical remote code execution vulnerability affecting Foxit PDF Reader version 11.2.1.53537, classified under CWE-476 as NULL Pointer Dereference. This vulnerability stems from insufficient input validation within the PDF document object handling mechanism, specifically when processing Doc objects that lack proper existence verification before operational execution. The flaw exists in the parser component responsible for interpreting PDF structures, where the software fails to validate whether referenced objects actually exist within the document context before attempting to access or manipulate them. This fundamental validation gap creates an exploitable condition that allows attackers to craft malicious PDF documents containing crafted Doc objects that trigger the vulnerability during normal document rendering operations.
The operational impact of this vulnerability extends beyond simple code execution to encompass complete system compromise when exploited successfully. Attackers can leverage this weakness by hosting malicious PDF files on compromised web servers or embedding them in phishing campaigns, requiring only user interaction to visit the malicious page or open the file. Once executed, the vulnerability enables arbitrary code execution within the context of the Foxit PDF Reader process, potentially allowing attackers to escalate privileges, install malware, or establish persistent access to the compromised system. This attack vector aligns with ATT&CK technique T1203 as it involves exploitation of a software vulnerability for code execution, while also potentially supporting lateral movement through privilege escalation or persistence mechanisms.
The technical exploitation of CVE-2022-28671 requires careful crafting of PDF documents that manipulate the Doc object structure to trigger the null pointer dereference condition. Attackers typically construct malicious PDF files containing malformed object references that cause the reader application to attempt operations on non-existent objects, leading to memory corruption and subsequent code execution. The vulnerability's exploitation is facilitated by the lack of proper bounds checking and object existence verification within the PDF parsing engine, creating a direct pathway for attackers to inject and execute malicious code. Security researchers have noted that this vulnerability can be particularly dangerous in enterprise environments where PDF documents are frequently opened and shared, making it a prime target for targeted attacks against organizations that rely heavily on PDF document processing.
Mitigation strategies for CVE-2022-28671 should include immediate patching of Foxit PDF Reader installations to the latest versions that contain the necessary security fixes. Organizations should implement strict PDF document scanning and validation processes, particularly for externally received documents, and consider deploying network-based intrusion detection systems that can identify and block malicious PDF content. Additionally, user education regarding the risks of opening untrusted PDF files remains crucial, as the vulnerability requires user interaction to be successfully exploited. Security teams should also monitor for indicators of compromise related to this vulnerability and ensure that all systems processing PDF documents have appropriate network segmentation and access controls in place to limit potential damage from successful exploitation attempts.