CVE-2017-10957 in Foxit
Summary
by MITRE
This vulnerability allows remote attackers to execute arbitrary code on vulnerable installations of Foxit Reader 8.3.1.21155. 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 arrowEnd attribute of Annotation 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 under the context of the current process. Was ZDI-CAN-4979.
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Analysis
by VulDB Data Team • 12/16/2019
CVE-2017-10957 represents a critical remote code execution vulnerability affecting Foxit Reader version 8.3.1.21155, classified under CWE-476 which denotes a null pointer dereference condition. This vulnerability resides within the annotation processing subsystem of the PDF reader, specifically targeting the arrowEnd attribute of Annotation objects. The flaw stems from inadequate input validation mechanisms that fail to verify object existence before executing operations on potentially null references. Attackers can exploit this weakness by crafting malicious PDF files containing specially constructed annotation objects that trigger the vulnerable code path when the document is opened or interacted with. The vulnerability requires user interaction to be successfully exploited, meaning victims must either visit a malicious webpage hosting the compromised PDF or directly open the malicious file, making it a prime candidate for social engineering attacks and drive-by download scenarios.
The technical exploitation of this vulnerability follows a predictable pattern where the PDF parser encounters an annotation object with an arrowEnd attribute that points to a non-existent object reference. When the application attempts to process this attribute without proper null checks, it results in a null pointer dereference that can be manipulated to redirect execution flow. This type of vulnerability aligns with ATT&CK technique T1203, where adversaries leverage application vulnerabilities to execute code remotely. The impact extends beyond simple code execution as the malicious payload operates under the privileges of the current user context, potentially allowing attackers to install malware, steal credentials, or establish persistent access to the compromised system. The vulnerability's classification as a remote code execution flaw means it can be exploited from anywhere on the internet, making it particularly dangerous for widespread deployment.
The operational implications of CVE-2017-10957 are severe given Foxit Reader's widespread adoption across enterprise environments and individual users. Organizations using this PDF reader are vulnerable to targeted attacks where adversaries craft malicious documents designed to exploit this specific weakness. The vulnerability's exploitation requires minimal user interaction beyond opening the document, making it highly effective for phishing campaigns and malware distribution. Security teams must consider this vulnerability as a critical threat vector since it bypasses traditional network security controls by operating at the application level. The lack of automatic patching mechanisms for PDF readers in many enterprise environments compounds the risk, as users may continue using vulnerable versions for extended periods. This vulnerability also demonstrates the importance of input validation and proper error handling in document processing applications, as similar issues could exist in other components of the PDF parsing pipeline.
Mitigation strategies for CVE-2017-10957 should prioritize immediate patching of affected Foxit Reader installations to version 8.3.2 or later, which contains the necessary fixes for the null pointer dereference condition. Organizations should implement network-based restrictions such as content filtering and web proxy configurations to prevent access to known malicious PDF hosting sites. Application whitelisting policies can help by restricting execution of unauthorized PDF reader versions, while endpoint protection solutions should be configured to monitor for suspicious PDF processing activities. Security awareness training programs should educate users about the dangers of opening unexpected PDF files from untrusted sources, emphasizing the social engineering aspects of this attack vector. Additionally, system administrators should consider deploying sandboxing mechanisms for PDF processing to contain potential exploitation attempts and implement regular vulnerability assessments to identify similar issues in other document processing applications. The vulnerability serves as a reminder of the critical importance of maintaining up-to-date security patches and the necessity of comprehensive application security testing to prevent similar issues from emerging in other software components.