CVE-2019-7811 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.
Once again VulDB remains the best source for vulnerability data.
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 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. This vulnerability stems from improper validation of input data when processing specific PDF file structures, creating an opportunity for attackers to read memory locations beyond the intended buffer boundaries. The flaw manifests when the application attempts to parse malformed or specially crafted PDF content that triggers an out-of-bounds memory access pattern. This type of vulnerability falls under the Common Weakness Enumeration category CWE-129, which specifically addresses improper validation of the length of input data, and more broadly encompasses CWE-125, which covers out-of-bounds read conditions. The security implications of this vulnerability are significant as successful exploitation can result in information disclosure, potentially exposing sensitive memory contents including encryption keys, user credentials, or other confidential data that may be stored in adjacent memory regions. Attackers can leverage this vulnerability by crafting malicious PDF files that, when opened by an affected version of Adobe Acrobat or Reader, trigger the out-of-bounds read condition. This technique aligns with ATT&CK framework tactic TA0001 (Initial Access) and technique T1193 (Spearphishing Attachment) where adversaries use malicious document attachments to deliver payloads. The operational impact extends beyond simple information disclosure as the vulnerability can potentially be chained with other exploits to achieve arbitrary code execution or privilege escalation depending on the execution environment. Organizations using affected versions of Adobe Acrobat and Reader face substantial risk, particularly in environments where users regularly open PDF documents from untrusted sources. The vulnerability represents a fundamental flaw in the PDF parsing engine's memory management, highlighting the critical importance of proper input validation and bounds checking in document processing applications. This type of vulnerability demonstrates the ongoing challenges in securing complex document formats that must handle extensive and varied data structures while maintaining memory safety. The attack surface is broad as PDF documents are widely used across enterprises and can be delivered through various channels including email, web downloads, and file sharing systems. Remediation efforts should prioritize immediate patching of all affected versions with the latest security updates from Adobe, along with implementing additional security controls such as PDF sandboxing, content filtering, and user education on safe document handling practices. Network-based defenses can include implementing strict file type controls and content inspection to prevent potentially malicious PDF files from reaching end users. The vulnerability serves as a reminder of the critical need for regular security updates and the importance of maintaining current software versions to protect against known exploits that target memory corruption vulnerabilities in widely used applications.