CVE-2018-15985 in Acrobat Reader
Summary
by MITRE
Adobe Acrobat and Reader versions 2019.008.20081 and earlier, 2019.008.20080 and earlier, 2019.008.20081 and earlier, 2017.011.30106 and earlier version, 2017.011.30105 and earlier version, 2015.006.30457 and earlier, and 2015.006.30456 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 • 08/05/2024
This vulnerability affects multiple versions of Adobe Acrobat and Reader software, specifically targeting the handling of malformed input data within the application's processing pipeline. The out-of-bounds read flaw occurs when the software attempts to access memory locations beyond the allocated buffer boundaries during document parsing operations. This type of vulnerability falls under the common weakness enumeration CWE-125 which describes out-of-bounds read conditions where programs access memory locations that are outside the intended buffer limits. The vulnerability manifests when the affected applications process specially crafted PDF files that contain malformed data structures, causing the memory access violation to occur during normal document rendering or parsing activities.
The technical implementation of this vulnerability exploits the lack of proper bounds checking in the software's memory management routines. When processing PDF documents, Adobe applications perform extensive parsing operations on various data structures including object arrays, string buffers, and metadata fields. The flaw occurs when these parsing routines fail to validate the size or boundaries of incoming data before attempting to read from memory locations. This allows an attacker to craft malicious PDF files that, when opened by vulnerable versions of Acrobat or Reader, trigger the out-of-bounds memory access. The vulnerability is particularly concerning because it operates at the application level and can be triggered through simple document opening activities without requiring any special privileges or user interaction beyond normal document consumption.
From an operational impact perspective, successful exploitation of this vulnerability can lead to information disclosure, where sensitive data from the application's memory space may be exposed to the attacker. The out-of-bounds read can potentially reveal memory contents including but not limited to stack contents, heap data, or other application state information that may contain credentials, session tokens, or other sensitive material. This information disclosure could enable further attacks including privilege escalation or targeted exploitation of other vulnerabilities within the application. The vulnerability operates within the ATT&CK framework under the technique T1059.007 for application execution and T1566 for malicious file delivery, as attackers can leverage this flaw through crafted PDF documents delivered via various attack vectors such as email or web-based delivery methods.
Mitigation strategies for this vulnerability primarily focus on immediate software updates and patches provided by Adobe. Organizations should prioritize updating to the latest versions of Adobe Acrobat and Reader that contain fixes for this out-of-bounds read vulnerability. Additionally, implementing defensive measures such as PDF sandboxing, content filtering, and restricted user permissions can help limit the potential impact of exploitation attempts. Network-based security controls including web application firewalls and content inspection systems should be configured to scan and block suspicious PDF files from entering the network perimeter. The vulnerability represents a classic example of how improper input validation can lead to memory safety issues and emphasizes the importance of robust bounds checking mechanisms in software development practices. Security teams should also consider implementing monitoring and alerting for unusual document processing activities that may indicate exploitation attempts, while maintaining awareness of the specific version ranges affected to ensure comprehensive patch management coverage.