CVE-2019-7801 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 • 09/17/2023
Adobe Acrobat and Reader applications contain a critical out-of-bounds read vulnerability that affects multiple version ranges across different release cycles. This vulnerability stems from insufficient input validation within the document parsing mechanisms that handle PDF files, specifically when processing malformed or specially crafted embedded objects. The flaw manifests when the application attempts to read memory locations beyond the bounds of allocated buffers during the parsing of PDF content structures. This type of vulnerability falls under the CWE-125 weakness category, which describes out-of-bounds read conditions where programs access memory locations that are outside the intended buffer boundaries. The vulnerability is particularly dangerous because it can be triggered through simple document manipulation without requiring user interaction beyond opening the malicious file, making it highly exploitable in phishing campaigns and targeted attacks.
The technical exploitation of this vulnerability occurs when the PDF parser encounters malformed data structures within embedded objects or streams, causing the application to attempt reading memory beyond the allocated buffer limits. This memory access violation can result in information disclosure, where sensitive data from adjacent memory locations may be exposed to the attacker. The vulnerability exists across multiple Adobe Acrobat and Reader versions, including 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. The out-of-bounds read condition typically occurs during the processing of PDF objects such as embedded fonts, images, or multimedia content where the application fails to properly validate the length or structure of incoming data before attempting to access it. This vulnerability aligns with the ATT&CK technique T1059.007 for application execution and T1068 for exploit for privilege escalation, as successful exploitation could potentially lead to further system compromise through information disclosure.
The operational impact of this vulnerability extends beyond simple information disclosure, as it can provide attackers with access to sensitive memory contents including encryption keys, user credentials, or other confidential data that may be stored in adjacent memory locations. This makes the vulnerability particularly dangerous in enterprise environments where users may open malicious PDF documents containing embedded exploits. Attackers can leverage this vulnerability through social engineering campaigns targeting end users, phishing emails, or compromised websites that deliver malicious PDF files. The vulnerability's presence across multiple version lines means that organizations running older Adobe products are particularly at risk, as these versions have not received the necessary patches to address the memory access validation issues. Security professionals should note that this vulnerability represents a significant risk to organizations that rely heavily on PDF document processing, as the attack surface is broad and the exploitation requires minimal user interaction beyond opening a malicious document. Organizations should prioritize immediate patching of affected versions and implement additional security controls such as PDF sandboxing, content filtering, and user education to mitigate the risk of exploitation.