CVE-2020-9711 in Acrobat Reader
Summary
by MITRE • 06/23/2026
Acrobat Reader versions 2020.009.20074, 2020.001.30002, 2017.011.30171, 2015.006.30523 and earlier are affected by an out-of-bounds read vulnerability that could lead to disclosure of sensitive memory. An attacker could leverage this vulnerability to disclose sensitive information. Exploitation of this issue requires user interaction in that a victim must open a malicious file.
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Analysis
by VulDB Data Team • 06/23/2026
This vulnerability represents a critical out-of-bounds read flaw affecting multiple versions of Adobe Acrobat Reader, specifically targeting the 2020, 2017, and 2015 release lines. The technical nature of this issue stems from improper bounds checking within the application's handling of maliciously crafted PDF files, creating an opportunity for attackers to access memory locations beyond the intended data boundaries. Such vulnerabilities fall under the CWE-129 category of Improper Validation of Array Index, which directly relates to the fundamental flaw in how the software validates input data before processing. The vulnerability operates at the memory management level where the application fails to properly validate the size and bounds of data structures when parsing PDF content, particularly affecting the document rendering engine that processes various file elements including embedded objects and streams.
The operational impact of this vulnerability extends beyond simple information disclosure, as it provides attackers with access to sensitive memory regions that may contain confidential data, application state information, or even credentials stored in memory. The requirement for user interaction through opening a malicious file creates a realistic attack vector that aligns with common social engineering tactics used in targeted attacks against enterprise environments and individual users. This characteristic places the vulnerability within the ATT&CK framework's technique T1203 - Exploitation for Client Execution, where adversaries leverage application vulnerabilities to execute malicious code or extract sensitive information. The attack scenario typically involves phishing emails containing crafted PDF documents that, when opened by victims, trigger the out-of-bounds read condition and potentially enable further exploitation through information leakage.
The memory disclosure aspect of this vulnerability poses significant risks to both individual user security and enterprise information protection, as leaked memory contents could include session tokens, cryptographic keys, or other sensitive application data that could be leveraged for subsequent attacks. Organizations running these vulnerable versions of Acrobat Reader face potential exposure through targeted phishing campaigns, where attackers craft malicious PDF documents designed to exploit this specific memory handling flaw. The remediation strategy should prioritize immediate patching of all affected versions with the latest Adobe security updates, as these releases contain fixed implementations of proper bounds checking and input validation mechanisms. Additionally, organizations should implement defensive measures including PDF file scanning, user education about suspicious document attachments, and network-based controls that can detect and block known malicious PDF indicators, ensuring comprehensive protection against exploitation attempts leveraging this vulnerability across their computing environments.