CVE-2018-17651 in Foxit
Summary
by MITRE
This vulnerability allows remote attackers to execute arbitrary code on vulnerable installations of Foxit Reader 9.2.0.9297. 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 the getItemState method of a TimeField. 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-6501.
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Analysis
by VulDB Data Team • 05/05/2020
This vulnerability in Foxit Reader 9.2.0.9297 represents a critical remote code execution flaw that demonstrates poor input validation practices in the application's handling of TimeField objects. The vulnerability specifically manifests within the getItemState method where the software fails to validate whether an object exists before performing operations on it. This type of flaw falls under the common weakness enumeration CWE-476 which categorizes null pointer dereference vulnerabilities as a significant security risk. The vulnerability's classification aligns with ATT&CK technique T1203 which describes exploitation of software vulnerabilities to gain unauthorized code execution. The flaw essentially creates a condition where an attacker can manipulate the application's behavior by providing malformed input that triggers the null pointer dereference.
The exploitation requires user interaction through either visiting a malicious webpage or opening a malicious file, making this a client-side attack vector that leverages social engineering techniques to deliver the payload. This user interaction requirement places the vulnerability in the context of phishing campaigns or drive-by download attacks where attackers craft convincing malicious documents or web pages to lure users into triggering the exploit. The attack surface is particularly concerning as Foxit Reader is a widely used PDF viewer application, making it an attractive target for threat actors seeking to compromise end-user systems. The vulnerability allows attackers to execute code within the context of the current process, potentially enabling full system compromise depending on the privileges of the user running the application.
The technical impact of this vulnerability extends beyond simple code execution as it represents a fundamental flaw in the application's object management and memory handling. When the getItemState method processes a TimeField object without proper validation, it creates a path where malicious input can cause the application to dereference a null pointer, leading to arbitrary code execution. This type of vulnerability is particularly dangerous because it can be exploited across different operating systems where Foxit Reader is deployed, and the attack can potentially bypass many traditional security controls. The vulnerability's exploitation could allow attackers to install malware, steal sensitive data, or establish persistent access to compromised systems. Organizations should consider this vulnerability as part of their broader security posture assessment and implement layered defenses including application whitelisting, network segmentation, and regular security updates to protect against such attacks.
Mitigation strategies should focus on immediate patching of the vulnerable Foxit Reader version, implementing network-based protections such as web proxies and content filtering to block malicious content, and educating users about the risks of opening untrusted PDF files or visiting suspicious websites. The vulnerability serves as a reminder of the importance of proper input validation and object existence checking in software development practices. Security teams should also monitor for indicators of compromise related to this vulnerability and consider implementing behavioral monitoring to detect anomalous execution patterns that might indicate exploitation attempts. Additionally, organizations should conduct regular vulnerability assessments to identify similar issues in other third-party applications and ensure comprehensive patch management processes are in place to address such vulnerabilities promptly.