CVE-2024-20747 in Acrobat 2020
Summary
by MITRE • 02/15/2024
Acrobat Reader versions 20.005.30539, 23.008.20470 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 bypass mitigations such as ASLR. 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 • 06/26/2026
This vulnerability represents a critical out-of-bounds read flaw affecting Adobe Acrobat Reader across multiple version ranges including 20.005.30539, 23.008.20470 and earlier versions. The technical nature of this issue stems from improper bounds checking within the PDF parsing functionality where the application fails to validate array indices or buffer limits when processing maliciously crafted PDF files. Such insufficient input validation creates opportunities for attackers to manipulate memory access patterns that extend beyond allocated buffer boundaries, potentially exposing sensitive data from adjacent memory regions.
The operational impact of this vulnerability extends beyond simple information disclosure as it can be leveraged to bypass critical security mitigations such as Address Space Layout Randomization which is designed to make memory addresses unpredictable and thus harder for attackers to target. When an attacker successfully exploits this out-of-bounds read condition, they may be able to extract memory contents that contain stack canaries, return addresses, or other security-related information that could facilitate more sophisticated attacks including arbitrary code execution. This vulnerability aligns with CWE-129 which describes improper validation of array indices and represents a classic example of how inadequate bounds checking can create fundamental security weaknesses in applications processing untrusted data.
The exploitation requirements for this vulnerability mandate user interaction through social engineering or phishing techniques where victims must open specifically crafted malicious PDF files to trigger the vulnerable code path. This user interaction requirement places this vulnerability in the category of client-side attacks that rely on user behavior rather than server-side exploitation methods. The attack surface is primarily limited to users who open PDF documents, making it particularly dangerous in enterprise environments where document sharing is common and security awareness may vary among employees.
Organizations should prioritize immediate patching of affected Acrobat Reader installations to remediate this vulnerability. Adobe has released security updates that address this issue, and system administrators should ensure all endpoints are updated with the latest versions. Additional mitigations include implementing email filtering solutions to block suspicious PDF attachments, deploying application whitelisting policies to restrict execution of unauthorized software, and conducting user awareness training to recognize potential social engineering attempts. The vulnerability demonstrates the importance of proper input validation and bounds checking in security-critical applications processing complex file formats, aligning with ATT&CK technique T1059.007 for execution through PDF files and highlighting the necessity of comprehensive security testing including fuzzing and memory safety analysis to identify such vulnerabilities before they can be exploited in the wild.