Security Experts:

Connect with us

Hi, what are you looking for?


Cloud Security

Foxit Plugs Multiple Security Holes in PDF Reader, Editor

Foxit Software this week released security updates for its PDF Reader and PDF Editor applications, to address multiple vulnerabilities, including some leading to remote code execution.

Foxit Software this week released security updates for its PDF Reader and PDF Editor applications, to address multiple vulnerabilities, including some leading to remote code execution.

Three of the vulnerabilities addressed by Foxit were identified by Cisco Talos researchers, all three leading to arbitrary code execution.

Tracked as CVE-2021-21831, CVE-2021-21870, and CVE-2021-21893, the bugs carry CVSS severity score of 8.8. Due to the manner in which certain JavaScript code or annotation objects are handled, a maliciously crafted PDF file may lead to the reuse of previously free memory and arbitrary code execution.

All three flaws are use-after-free vulnerabilities in the JavaScript engine of PDF Reader that an attacker could exploit by tricking the target into opening a malicious PDF file. The vulnerability could also be exploited via a malicious website, provided that the victim has Foxit’s browser plugin enabled, according to a Cisco Talos advisory.

[ Read: Reasons for Cloud Misconfigurations are Many and Complex ]

Foxit also addressed multiple use-after-free vulnerabilities in the way the applications handle the annotation objects in certain PDF files, “if the same Annotation dictionary is referenced in the page structures for different pages.”

The vulnerabilities occur when an Annotation dictionary has multiple annotation objects associated to it and could lead to remote code execution, Foxit explained.

Another security issue covered with the update is a use-after-free when traversing bookmark nodes in certain PDF files, and which too could lead to the execution of code remotely.

Foxit also addressed potential security issues related to the parsing of XML data with too many embedded nodes, to the execution of the submitForm function, or the parsing of specially crafted PDF files.

Some of these vulnerabilities were also found to impact the macOS versions of Foxit’s applications, and patches were released for them as well.

Related: Foxit Patches Code Execution Vulnerabilities in PDF Software

Related: Foxit Reader Update Patches Over 100 Vulnerabilities

Written By

Ionut Arghire is an international correspondent for SecurityWeek.

Click to comment

Daily Briefing Newsletter

Subscribe to the SecurityWeek Email Briefing to stay informed on the latest threats, trends, and technology, along with insightful columns from industry experts.

Join this webinar to learn best practices that organizations can use to improve both their resilience to new threats and their response times to incidents.


Join this live webinar as we explore the potential security threats that can arise when third parties are granted access to a sensitive data or systems.


Expert Insights

Related Content

Application Security

Cycode, a startup that provides solutions for protecting software source code, emerged from stealth mode on Tuesday with $4.6 million in seed funding.

Data Protection

The CRYSTALS-Kyber public-key encryption and key encapsulation mechanism recommended by NIST for post-quantum cryptography has been broken using AI combined with side channel attacks.


Less than a week after announcing that it would suspended service indefinitely due to a conflict with an (at the time) unnamed security researcher...

Data Protection

The cryptopocalypse is the point at which quantum computing becomes powerful enough to use Shor’s algorithm to crack PKI encryption.


The changing nature of what we still generally call ransomware will continue through 2023, driven by three primary conditions.


WASHINGTON - Cyberattacks are the most serious threat facing the United States, even more so than terrorism, according to American defense experts. Almost half...


No one combatting cybercrime knows everything, but everyone in the battle has some intelligence to contribute to the larger knowledge base.

Risk Management

The supply chain threat is directly linked to attack surface management, but the supply chain must be known and understood before it can be...