CVE-2017-11229 in Acrobat Reader
Summary
by MITRE
Adobe Acrobat Reader 2017.009.20058 and earlier, 2017.008.30051 and earlier, 2015.006.30306 and earlier, and 11.0.20 and earlier has a security bypass vulnerability when manipulating Forms Data Format (FDF).
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Analysis
by VulDB Data Team • 08/30/2024
Adobe Acrobat Reader contains a security bypass vulnerability in versions up to 2017.009.20058, 2017.008.30051, 2015.006.30306, and 11.0.20 that affects Forms Data Format FDF manipulation. This vulnerability stems from insufficient validation of FDF files which allows malicious actors to bypass intended security controls during form processing. The flaw exists in the way Acrobat Reader handles FDF data structures, particularly when processing external form data that can be embedded within PDF documents. When a user opens a maliciously crafted PDF containing FDF content, the vulnerability can be exploited to circumvent access controls and potentially execute unauthorized operations within the application context. The security bypass occurs because the software fails to properly sanitize or validate FDF data before processing, allowing crafted payloads to manipulate the form handling mechanisms. This vulnerability is classified under CWE-284 which addresses improper access control issues, and aligns with ATT&CK technique T1059.007 for script execution through application-specific interfaces. The impact of this vulnerability extends beyond simple data manipulation as it can enable attackers to gain unauthorized access to form fields, potentially leading to privilege escalation or data exfiltration. The flaw is particularly concerning because it operates at the application layer where user interaction is required, making it suitable for social engineering attacks. Attackers can craft malicious PDF documents that appear legitimate while containing hidden FDF manipulation code. This vulnerability demonstrates poor input validation practices and highlights the importance of proper data sanitization in document processing applications. The exploitation requires user interaction with a malicious document, making it a medium-risk vulnerability that can be effectively mitigated through user education and proper patch management. Organizations should prioritize updating to patched versions of Adobe Acrobat Reader to prevent potential exploitation of this security bypass vulnerability.
The technical nature of this vulnerability involves the improper handling of FDF data structures within the Acrobat Reader application. When processing FDF files, the software does not adequately validate the integrity or authenticity of the data, allowing attackers to inject malicious code or manipulate form field behaviors. This flaw specifically affects the form data processing subsystem where FDF files are interpreted and applied to PDF forms. The vulnerability represents a classic case of insufficient validation where the application trusts input data without proper sanitization checks. The exploitation mechanism relies on the application's failure to implement robust access control measures during FDF processing, enabling attackers to manipulate form fields or bypass intended security restrictions. From a cybersecurity perspective, this vulnerability falls under the category of application-level exploits that leverage weaknesses in document parsing and form handling capabilities. The impact is significant because it allows for unauthorized manipulation of form data and can potentially lead to broader system compromise if the form fields are connected to sensitive operations or data access points.
Mitigation strategies for this vulnerability should include immediate patch deployment to all affected versions of Adobe Acrobat Reader, along with implementation of network-level controls to monitor and block suspicious FDF content. Organizations should establish strict policies regarding PDF document handling and implement user awareness training to recognize potentially malicious documents. The vulnerability can be addressed through proper input validation mechanisms that enforce strict sanitization of FDF data before processing, ensuring that all external form data is properly authenticated and validated. Network administrators should consider implementing content filtering solutions that can detect and block suspicious PDF files containing malformed FDF structures. The security controls should also include monitoring for unusual form processing activities that might indicate exploitation attempts. Regular security assessments should be conducted to identify potential vulnerabilities in document processing applications, with particular attention to input validation and access control mechanisms. Organizations should also consider implementing sandboxing techniques for PDF document processing to limit the potential impact of successful exploitation attempts. This vulnerability underscores the critical importance of maintaining up-to-date security patches and implementing defense-in-depth strategies to protect against application-level exploits. The remediation approach should combine immediate patching with long-term security hardening measures to prevent similar vulnerabilities from emerging in the future.