CVE-2019-8173 in Acrobat Reader
Summary
by MITRE
Adobe Acrobat and Reader versions , 2019.012.20040 and earlier, 2017.011.30148 and earlier, 2017.011.30148 and earlier, 2015.006.30503 and earlier, and 2015.006.30503 and earlier have an out-of-bounds read vulnerability. Successful exploitation could lead to information disclosure .
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Analysis
by VulDB Data Team • 01/16/2024
Adobe Acrobat and Reader applications contain a critical out-of-bounds read vulnerability that affects multiple versions across different release cycles. This vulnerability resides in the PDF parsing functionality where the software fails to properly validate array indices when processing malformed PDF files. The flaw allows attackers to craft specially designed PDF documents that trigger memory access violations when the application attempts to read data beyond the allocated buffer boundaries. The vulnerability is classified under CWE-125 as an out-of-bounds read condition, which represents a fundamental memory safety issue that can be exploited to extract sensitive information from the application's memory space.
The technical exploitation of this vulnerability occurs when a malicious PDF file contains crafted data structures that cause the Acrobat or Reader application to access memory locations that are not properly validated. During normal operation, PDF parsers maintain strict bounds checking to ensure that array accesses remain within allocated memory regions. However, in vulnerable versions, this validation mechanism fails, allowing the parser to read beyond the intended memory boundaries and potentially expose confidential data such as stack contents, heap data, or other sensitive information stored in memory. The out-of-bounds read can occur during parsing of various PDF elements including embedded objects, arrays, or streams that are processed by the vulnerable parsing components.
The operational impact of this vulnerability extends beyond simple information disclosure to potentially enable more sophisticated attacks within the context of the compromised application. Attackers can leverage this vulnerability to extract memory contents that may include encryption keys, user credentials, or other sensitive data that could be used for further exploitation. The vulnerability's presence in multiple version ranges suggests a widespread issue affecting both current and legacy installations, making it particularly dangerous for organizations with diverse software environments. This type of vulnerability aligns with ATT&CK technique T1059.007 for command and scripting interpreter, where the extracted information could be used to develop more targeted attacks against the system or users. The vulnerability's exploitation requires minimal user interaction, typically only opening a malicious PDF file, making it particularly effective for phishing campaigns or drive-by download attacks.
Organizations should implement immediate mitigation strategies including updating to the latest versions of Adobe Acrobat and Reader where the vulnerability has been patched. The patch addresses the out-of-bounds read issue by implementing proper bounds checking mechanisms and input validation for PDF parsing operations. Additional defensive measures include deploying PDF sandboxing technologies, implementing network-based intrusion detection systems that can identify malicious PDF content, and establishing strict email filtering policies to prevent delivery of potentially malicious PDF attachments. Security teams should also conduct comprehensive vulnerability assessments to identify all systems running vulnerable versions and ensure proper patch management procedures are in place to prevent similar issues from occurring in the future. The vulnerability demonstrates the importance of maintaining up-to-date software versions and implementing layered security controls to protect against memory safety issues that can compromise system integrity.