CVE-2018-17609 in PhantomPDF
Summary
by MITRE
Foxit PhantomPDF and Reader before 9.3 allow remote attackers to execute arbitrary code or cause a denial of service (use-after-free) because properties of Annotation objects are mishandled. This relates to one of five distinct types of Annotation objects.
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Analysis
by VulDB Data Team • 03/28/2020
CVE-2018-17609 represents a critical use-after-free vulnerability affecting Foxit PhantomPDF and Reader versions prior to 9.3. This vulnerability stems from improper handling of annotation object properties within the PDF processing engine, creating a remote code execution vector that can be exploited by attackers. The flaw specifically impacts one of five distinct annotation object types, indicating a targeted issue within the annotation processing subsystem rather than a complete breakdown of the PDF parser. The vulnerability occurs when the software fails to properly manage memory references to annotation objects after they have been freed, allowing malicious actors to manipulate the memory state and potentially execute arbitrary code or induce denial of service conditions.
The technical nature of this vulnerability aligns with CWE-416, which describes use-after-free conditions where memory is accessed after it has been freed by the program. This particular flaw demonstrates how improper memory management in PDF annotation processing can create persistent security risks. Attackers can craft malicious PDF documents containing specially constructed annotation objects that trigger the vulnerable code path when the software attempts to process these elements. The use-after-free condition allows for memory corruption that can be leveraged to overwrite critical memory locations, potentially leading to arbitrary code execution with the privileges of the affected application. The vulnerability's remote exploitability means that attackers can deliver malicious payloads through web browsers, email attachments, or other delivery mechanisms without requiring local system access.
From an operational perspective, this vulnerability poses significant risks to organizations relying on Foxit PDF readers and viewers for document processing. The remote code execution capability means that a single malicious PDF document could compromise user systems, potentially leading to data breaches, system compromise, or further lateral movement within networks. The denial of service aspect can also be leveraged to disrupt business operations by causing applications to crash or become unresponsive. This vulnerability affects a broad user base since PDF readers are commonly used across various industries for document sharing and collaboration, making it a prime target for exploitation campaigns. Security teams must consider the potential for widespread impact when addressing this vulnerability, as it could be exploited in targeted attacks against specific organizations or used in mass phishing campaigns.
Organizations should prioritize immediate patching of Foxit PhantomPDF and Reader installations to version 9.3 or later, where the memory management issues have been addressed. System administrators should also implement additional security controls including PDF content filtering, sandboxing mechanisms, and network-based protections to mitigate potential exploitation attempts. The vulnerability demonstrates the importance of proper memory management in security-critical applications and highlights the need for regular security assessments of third-party software components. Organizations should also consider implementing user education programs to raise awareness about the risks of opening untrusted PDF documents and establish robust incident response procedures for potential exploitation attempts. The remediation process should include thorough testing of patched versions to ensure that the fix does not introduce compatibility issues with existing workflows or document processing requirements.