CVE-2018-5022 in Acrobat Reader
Summary
by MITRE
Adobe Acrobat and Reader 2018.011.20040 and earlier, 2017.011.30080 and earlier, and 2015.006.30418 and earlier versions have an Out-of-bounds read vulnerability. Successful exploitation could lead to information disclosure.
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Analysis
by VulDB Data Team • 08/11/2024
Adobe Acrobat and Reader versions prior to 2018.011.20040, 2017.011.30080, and 2015.006.30418 contain a critical out-of-bounds read vulnerability that stems from improper input validation within the document parsing functionality. This vulnerability falls under the CWE-125 weakness category, which specifically addresses out-of-bounds read conditions where an application attempts to read memory locations beyond the allocated buffer boundaries. The flaw occurs when processing malformed pdf documents that contain crafted malicious data structures, particularly within the document object hierarchy or stream parsing mechanisms. Attackers can exploit this vulnerability by crafting specially formatted pdf files that trigger the out-of-bounds memory access during document rendering or parsing operations. The technical implementation involves the application failing to properly validate array indices or buffer limits when processing certain pdf elements, leading to memory corruption that can result in information disclosure. This vulnerability is particularly concerning as it can be triggered through simple document opening operations, making it highly accessible to attackers who can deliver malicious pdf files via email attachments, web downloads, or file sharing platforms. The exploitation process typically involves creating a pdf file with malformed data structures that cause the vulnerable parsing code to access memory locations outside the intended buffer boundaries, potentially exposing sensitive information from adjacent memory regions. The operational impact extends beyond simple information disclosure to potentially enable more sophisticated attacks such as remote code execution or privilege escalation depending on the specific memory layout and operating system environment. From an adversary perspective, this vulnerability aligns with ATT&CK technique T1203 - Exploitation for Client Execution, as it allows for arbitrary code execution through crafted pdf documents. Organizations using affected versions of Adobe Acrobat and Reader face significant risk exposure, particularly in environments where users frequently open pdf documents from untrusted sources. The vulnerability represents a critical security gap in Adobe's document processing stack, as it demonstrates inadequate bounds checking in memory management operations. Security professionals should consider this vulnerability as part of broader exploitation frameworks targeting document readers, especially in phishing campaigns or targeted attacks where adversaries seek to leverage client-side vulnerabilities. The information disclosure aspect of this vulnerability can potentially expose sensitive data such as encryption keys, user credentials, or system memory contents that may be stored in adjacent memory locations. Mitigation strategies include immediate patching of all affected Adobe Acrobat and Reader installations, implementation of pdf document filtering and sandboxing mechanisms, and network-based protections such as web application firewalls that can detect and block malicious pdf content. Additionally, user education regarding the dangers of opening pdf files from untrusted sources remains crucial in reducing the attack surface. The vulnerability highlights the importance of robust input validation and memory safety practices in document processing applications, particularly those handling complex binary formats like pdf. Organizations should also consider implementing automated vulnerability scanning tools to identify systems running outdated versions of Adobe software and ensure comprehensive patch management procedures are in place to prevent exploitation of similar vulnerabilities in the future.