CVE-2019-7776 in Acrobat Reader
Summary
by MITRE
Adobe Acrobat and Reader versions 2019.010.20100 and earlier, 2019.010.20099 and earlier, 2017.011.30140 and earlier, 2017.011.30138 and earlier, 2015.006.30495 and earlier, and 2015.006.30493 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 • 06/13/2024
Adobe Acrobat and Reader applications contain a critical out-of-bounds read vulnerability that affects multiple versions across different release cycles. This vulnerability stems from insufficient input validation within the document parsing functionality, specifically when processing malformed PDF files. The flaw allows an attacker to craft malicious PDF documents that trigger memory access violations when the vulnerable software attempts to read data beyond the allocated buffer boundaries. The vulnerability has been classified under CWE-125 as an out-of-bounds read condition, which represents a fundamental memory safety issue that can lead to unpredictable behavior and potential information disclosure. When exploited, this vulnerability can cause the application to read memory locations that contain sensitive data such as encryption keys, user credentials, or system information that should remain protected.
The technical implementation of this vulnerability occurs during the parsing of PDF objects where the software fails to properly validate array indices or string lengths before accessing memory locations. Attackers can leverage this weakness by embedding specially crafted malicious content within PDF files that, when opened by the vulnerable software, triggers the out-of-bounds memory access. This type of vulnerability is particularly dangerous because it can be exploited through social engineering attacks where users are tricked into opening malicious documents via email attachments or compromised websites. The exploitation process typically involves crafting a PDF document that contains malformed data structures designed to cause the application to read beyond allocated memory segments, potentially exposing sensitive information stored in adjacent memory locations.
From an operational perspective, the impact of this vulnerability extends beyond simple information disclosure to potentially enable more sophisticated attacks. The out-of-bounds read can reveal memory addresses, stack contents, or other sensitive data that might aid in developing more advanced exploitation techniques such as remote code execution or privilege escalation. Security researchers have noted that this vulnerability aligns with ATT&CK technique T1059.007 for command and scripting interpreter, as the information disclosure can provide attackers with data needed to craft more targeted attacks. Organizations using affected versions of Adobe Acrobat and Reader face significant risk exposure, particularly in environments where users regularly handle PDF documents from untrusted sources. The vulnerability affects not only end-user systems but also enterprise environments where PDF processing is automated or integrated into business workflows, potentially creating multiple attack vectors.
Organizations should immediately implement mitigation strategies to protect against exploitation of this vulnerability. The primary recommendation involves updating to the latest versions of Adobe Acrobat and Reader where the vulnerability has been patched. Adobe has released security updates for all affected versions, and organizations should prioritize deployment of these patches across all affected systems. Additionally, implementing content filtering solutions that scan PDF documents for malicious content can provide an additional layer of protection. Network administrators should consider implementing web application firewalls or content inspection tools that can detect and block suspicious PDF files before they reach end-user systems. Security monitoring should include detection of unusual memory access patterns or application crashes that might indicate exploitation attempts. The vulnerability also underscores the importance of user education and awareness programs to prevent social engineering attacks that rely on tricking users into opening malicious PDF documents. Organizations should also consider implementing principle of least privilege controls to limit the potential impact if exploitation does occur, ensuring that Adobe Reader applications run with minimal required privileges.