CVE-2018-4985 in Acrobat Reader
Summary
by MITRE
Adobe Acrobat and Reader versions 2018.011.20038 and earlier, 2017.011.30079 and earlier, and 2015.006.30417 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 • 07/21/2024
Adobe Acrobat and Reader applications contain a critical out-of-bounds read vulnerability that affects multiple version ranges including 2018.011.20038 and earlier, 2017.011.30079 and earlier, and 2015.006.30417 and earlier. This vulnerability resides in the handling of PDF documents and represents a classic memory safety issue that falls under CWE-125, which specifically addresses out-of-bounds read conditions. The flaw occurs when the software processes malformed PDF files that contain specially crafted data structures, leading to improper bounds checking during memory access operations. When exploited, this vulnerability allows attackers to read data from memory locations that should not be accessible, potentially exposing sensitive information such as stack contents, heap data, or other memory segments that may contain credentials, encryption keys, or proprietary information. The security implications extend beyond simple information disclosure as this type of vulnerability can serve as a stepping stone for more sophisticated attacks, aligning with ATT&CK technique T1005 for data from local system and T1059 for command and scripting interpreter. The vulnerability is particularly concerning because it can be triggered through simple document interaction, requiring no special privileges or complex exploitation chains. Attackers can craft malicious PDF files that, when opened by an affected version of Adobe Reader or Acrobat, will cause the application to read beyond allocated memory boundaries, potentially revealing confidential data stored in adjacent memory locations. This type of vulnerability demonstrates the importance of proper input validation and memory management practices in document processing software, as PDF readers must handle a wide variety of file formats and data structures while maintaining strict security boundaries. The impact is significant across enterprise environments where these applications are widely deployed, as a single compromised document could potentially expose sensitive corporate or personal data. Organizations should prioritize immediate patching of affected systems and implement additional security controls such as PDF sandboxing, restricted file opening permissions, and network-based content filtering to mitigate the risk of exploitation. The vulnerability also highlights the ongoing challenges in securing document processing applications where the complexity of file formats and the need for extensive feature support create numerous potential attack surfaces that require continuous security assessment and remediation efforts.
This vulnerability represents a fundamental flaw in memory management that can be exploited through the manipulation of PDF document structures. The out-of-bounds read condition occurs during the parsing and rendering of PDF content, where the application fails to properly validate array indices or buffer sizes before accessing memory locations. The technical nature of this issue places it squarely within the realm of software security vulnerabilities that can lead to information disclosure and potentially more severe consequences. From an operational standpoint, the vulnerability affects a broad range of users who rely on Adobe Reader and Acrobat for document viewing and processing, making it a high-priority security concern for organizations of all sizes. The exploitation process is relatively straightforward for attackers who understand PDF format internals, as they need only create a malicious document that triggers the specific memory access pattern that leads to the out-of-bounds read. The vulnerability's classification under CWE-125 emphasizes the need for proper array bounds checking and memory access validation in software development practices. Security researchers have noted that such vulnerabilities are particularly dangerous because they can be exploited in the context of user interaction, meaning that simply opening a malicious document could compromise system security. The potential for information disclosure through this vulnerability extends to any data that might be stored in memory regions adjacent to the vulnerable code execution paths, including but not limited to user credentials, system configuration details, or application-specific data that could be leveraged in subsequent attack phases. The remediation approach must consider both immediate patch deployment and longer-term architectural improvements in how PDF processing software handles potentially malicious input. Organizations implementing security controls should consider the broader implications of this vulnerability within their overall security posture, particularly in environments where document sharing and collaboration are common practices. The vulnerability also underscores the importance of maintaining updated security practices and the need for continuous monitoring of software applications for known security flaws that could be exploited by threat actors.