CVE-2020-13570 in Foxit
Summary
by MITRE • 12/23/2020
A use-after-free vulnerability exists in the JavaScript engine of Foxit Software’s PDF Reader, version 10.1.0.37527. A specially crafted PDF document can trigger the reuse of previously free memory which can lead to arbitrary code execution. An attacker needs to trick the user to open the malicious file to trigger this vulnerability. If the browser plugin extension is enabled, visiting a malicious site can also trigger the vulnerability.
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Analysis
by VulDB Data Team • 07/22/2026
This vulnerability represents a critical use-after-free condition in Foxit PDF Reader's JavaScript engine, specifically affecting version 10.1.0.37527 and potentially earlier versions. The flaw occurs when the application processes specially crafted PDF documents that contain malformed JavaScript code designed to manipulate memory pointers after objects have been freed. This type of vulnerability falls under the common weakness enumeration CWE-416 which categorizes use-after-free conditions as a serious memory safety issue. The attack vector requires user interaction through opening malicious PDF files, though browser plugin extensions can also serve as an entry point when users visit compromised websites.
The technical execution of this vulnerability involves sophisticated exploitation techniques that leverage the JavaScript engine's memory management flaws. When processing malformed PDF content, the application fails to properly validate object lifecycles, allowing attackers to manipulate freed memory pointers and potentially redirect execution flow. This creates a pathway for arbitrary code execution with the privileges of the victim user, making it particularly dangerous in enterprise environments where PDF readers are frequently used. The vulnerability's impact is amplified by the widespread adoption of Foxit Reader across various industries and operating systems.
Operational consequences of this vulnerability extend beyond simple exploitation as it can enable advanced persistent threats and privilege escalation attacks. Security researchers have noted that such use-after-free vulnerabilities often provide attackers with opportunities to bypass modern security mitigations including address space layout randomization and data execution prevention mechanisms. The attack surface is significant since PDF readers are commonly used for document sharing in business environments, educational institutions, and government agencies where sensitive information is handled regularly. Organizations may experience data breaches, system compromise, or unauthorized access to confidential documents if this vulnerability remains unpatched.
Mitigation strategies should include immediate patch deployment from Foxit Software as the primary defense mechanism against exploitation attempts. System administrators should implement application whitelisting policies to restrict execution of unsigned PDF readers and disable unnecessary browser plugin extensions that could serve as attack vectors. Network-based protections such as web proxies with PDF content filtering can help prevent users from accessing malicious websites containing exploit code. Additionally, user education regarding safe PDF handling practices and awareness of social engineering tactics commonly employed in phishing campaigns targeting these vulnerabilities is essential for comprehensive security postures. Organizations should also consider implementing endpoint detection and response solutions that can monitor for suspicious memory access patterns indicative of use-after-free exploitation attempts.