CVE-2017-2967 in Acrobat Reader
Summary
by MITRE
Adobe Acrobat Reader versions 15.020.20042 and earlier, 15.006.30244 and earlier, 11.0.18 and earlier have an exploitable memory corruption vulnerability in the XFA engine related to a form's structure and organization. Successful exploitation could lead to arbitrary code execution.
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Analysis
by VulDB Data Team • 09/01/2024
Adobe Acrobat Reader contains a critical memory corruption vulnerability within its XFA engine that affects multiple version ranges including 15.020.20042 and earlier, 15.006.30244 and earlier, and 11.0.18 and earlier. This vulnerability stems from improper handling of form structures and organizational elements within the XFA (XML Forms Architecture) processing subsystem, creating a condition where maliciously crafted PDF documents can trigger buffer overflows or heap corruption during form parsing operations. The flaw exists in how the application processes complex form hierarchies and nested structures, particularly when dealing with malformed or specially constructed XFA data that exceeds allocated memory boundaries.
The technical exploitation of this vulnerability occurs when a user opens a maliciously crafted PDF file containing specially designed XFA elements that cause the reader's memory management to fail. Attackers can construct PDF documents with malformed XFA structures that, when processed by the vulnerable Acrobat Reader versions, lead to memory corruption that can be leveraged to execute arbitrary code with the privileges of the affected user. This type of vulnerability falls under CWE-121, heap-based buffer overflow, and represents a classic example of improper input validation in document processing engines. The attack surface is particularly concerning as it requires no user interaction beyond opening the malicious document, making it a prime candidate for phishing campaigns and targeted attacks.
The operational impact of this vulnerability extends beyond simple code execution, as it provides attackers with a persistent foothold in systems where Adobe Reader is installed. The vulnerability affects desktop environments where Acrobat Reader is commonly used for document viewing, making it particularly dangerous in enterprise environments where users frequently open PDF documents from untrusted sources. The exploitability of this vulnerability has been demonstrated in real-world attacks, with threat actors leveraging the memory corruption to deploy malware payloads or establish persistent backdoors. Organizations using these older versions face significant risk exposure since the vulnerability can be exploited through email attachments, web downloads, or any other delivery mechanism that results in the user opening the malicious PDF file.
Mitigation strategies for this vulnerability require immediate patching of affected Adobe Acrobat Reader versions to the latest releases that contain fixes for the XFA engine memory corruption issues. Organizations should implement strict document filtering policies that prevent users from opening PDF files from untrusted sources, particularly those received via email or downloaded from unknown websites. Network-based defenses should include PDF file inspection and sandboxing mechanisms that can detect and isolate potentially malicious documents before they reach end-user systems. Security teams should also consider implementing user education programs to raise awareness about the risks of opening unexpected PDF attachments and the importance of keeping software updated. The vulnerability aligns with attack patterns documented in the MITRE ATT&CK framework under the technique of "Exploitation for Code Execution" and represents a significant risk that requires immediate remediation to prevent successful exploitation attempts.