CVE-2018-15923 in Acrobat Reader
Summary
by MITRE
Adobe Acrobat and Reader versions 2018.011.20063 and earlier, 2017.011.30102 and earlier, and 2015.006.30452 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 • 08/07/2024
Adobe Acrobat and Reader applications contain a critical out-of-bounds read vulnerability that affects multiple version ranges including 2018.011.20063 and earlier, 2017.011.30102 and earlier, and 2015.006.30452 and earlier releases. This vulnerability stems from improper input validation within the software's document processing mechanisms, specifically when handling malformed or specially crafted PDF files. The flaw manifests as an out-of-bounds memory read operation that occurs during the parsing of certain PDF objects, particularly those related to font handling and embedded content processing. When a maliciously constructed PDF document is opened, the application attempts to access memory locations beyond the allocated buffer boundaries, resulting in unpredictable behavior and potential information disclosure.
The technical nature of this vulnerability aligns with CWE-125, which describes out-of-bounds read conditions in software systems. This type of flaw represents a fundamental memory safety issue that can be exploited by attackers to extract sensitive information from the application's memory space. The vulnerability occurs during the parsing phase when the software fails to properly validate array indices or buffer boundaries before accessing memory locations. Attackers can craft PDF files that trigger this condition by manipulating specific fields within the document structure, particularly those related to font dictionaries and embedded object references. The out-of-bounds read operation may expose stack contents, heap data, or other sensitive information that could be leveraged for further exploitation attempts.
The operational impact of this vulnerability extends beyond simple information disclosure, as it creates potential pathways for more sophisticated attacks within the context of a compromised system. When exploited successfully, the vulnerability allows attackers to extract potentially sensitive data from the application's memory, which could include cryptographic keys, user credentials, or other confidential information. The vulnerability's presence in widely deployed software versions means that organizations using affected Adobe Acrobat and Reader installations face significant risk exposure, particularly in environments where users regularly open PDF documents from untrusted sources. This makes the vulnerability particularly dangerous in enterprise settings where PDF documents are commonly used for business communications and document sharing.
Organizations should prioritize immediate remediation by updating to the latest versions of Adobe Acrobat and Reader that contain patches addressing this vulnerability. Adobe has released security updates specifically targeting CVE-2018-15923, and administrators should ensure all affected systems receive these patches promptly. Additionally, implementing defensive measures such as PDF sandboxing, content filtering, and restricted user permissions can help mitigate the risk of exploitation. Network-based protections including web application firewalls and email security gateways should be configured to scan and block suspicious PDF attachments. The vulnerability also aligns with several ATT&CK techniques including T1059 for execution through document macros and T1068 for local privilege escalation, making comprehensive security measures essential for protecting against potential exploitation chains. Regular security assessments and vulnerability scanning should be conducted to identify any remaining instances of the vulnerable software within the organization's infrastructure.