CVE-2020-9705 in Acrobat Reader
Summary
by MITRE
Adobe Acrobat and Reader versions 2020.009.20074 and earlier, 2020.001.30002, 2017.011.30171 and earlier, and 2015.006.30523 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 • 11/08/2020
Adobe Acrobat and Reader applications contain a critical out-of-bounds read vulnerability that affects multiple product versions including 2020.009.20074 and earlier, 2020.001.30002, 2017.011.30171 and earlier, and 2015.006.30523 and earlier. This vulnerability stems from improper bounds checking within the software's handling of specific file formats, particularly those related to pdf document parsing and processing. 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. This type of vulnerability falls under the common weakness enumeration CWE-125 which specifically addresses out-of-bounds read conditions in software implementations.
The exploitation of this vulnerability occurs when a user opens a specially crafted pdf file that contains malformed data structures designed to trigger the out-of-bounds read condition. When the affected Adobe applications process such files, the software attempts to access memory locations that are outside the intended buffer limits, potentially exposing sensitive information stored in adjacent memory regions. The information disclosure aspect of this vulnerability represents a significant security risk as it could reveal confidential data including system memory contents, encryption keys, or other sensitive information that may be stored in the memory space adjacent to the vulnerable buffer. This type of information disclosure can serve as a foundation for more sophisticated attacks including privilege escalation or further exploitation attempts.
From an operational perspective, this vulnerability presents a substantial risk to organizations that rely on Adobe Acrobat and Reader for document processing and viewing. The attack vector typically involves social engineering techniques where users are tricked into opening malicious pdf files through email attachments, web downloads, or other delivery mechanisms. The impact extends beyond simple information disclosure as it can potentially provide attackers with enough information to develop more targeted attacks against the affected systems. Security analysts should note that this vulnerability aligns with ATT&CK technique T1059 which encompasses execution through various software interfaces, and T1068 which relates to privilege escalation through application vulnerabilities.
Organizations should immediately implement mitigation strategies including prompt application updates to the latest versions of Adobe Acrobat and Reader that contain patches for this vulnerability. System administrators should also consider implementing additional protective measures such as pdf file content filtering, restricted user permissions for document handling, and network-based security controls that can detect and block potentially malicious pdf content. The vulnerability's classification as a memory safety issue makes it particularly susceptible to exploitation in environments where users have elevated privileges or where the applications are used to process untrusted documents. Regular security assessments and vulnerability scanning should be conducted to ensure that all affected systems are properly patched and that the organization maintains adequate protection against similar memory corruption vulnerabilities in the future.