CVE-2018-5026 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 represents a significant security flaw in the document processing engine. This vulnerability falls under the Common Weakness Enumeration category CWE-125, which specifically addresses out-of-bounds read conditions where an application attempts to access memory locations beyond the allocated buffer boundaries. The flaw occurs during the parsing of PDF documents, particularly when processing malformed or specially crafted PDF files that contain maliciously constructed data structures. When the vulnerable software attempts to read data beyond the intended buffer limits, it may inadvertently access adjacent memory locations containing sensitive information such as stack contents, heap data, or other application memory segments.
The exploitation of this vulnerability can result in information disclosure, where attackers can potentially extract sensitive data from the application's memory space. This type of vulnerability is particularly dangerous because it can be leveraged to obtain confidential information that might include cryptographic keys, user credentials, or other sensitive data stored in memory. The attack typically requires the victim to open a maliciously crafted PDF file, which can be delivered through various attack vectors including email attachments, web downloads, or compromised websites. The vulnerability's impact is amplified by the widespread use of Adobe Acrobat and Reader across enterprise environments and individual users, making it an attractive target for adversaries seeking to gain unauthorized access to sensitive information.
From an operational perspective, this vulnerability presents a substantial risk to organizations that rely heavily on PDF document processing and sharing. The out-of-bounds read condition can potentially be chained with other vulnerabilities to achieve more severe outcomes including arbitrary code execution, though the current disclosure focuses on information disclosure capabilities. Security analysts should note that this vulnerability aligns with the attack pattern described in the MITRE ATT&CK framework under the technique T1059.007 for execution through PDF files and T1566 for initial access via malicious documents. The vulnerability's exploitation requires minimal user interaction beyond opening the malicious document, making it particularly effective for social engineering campaigns. Organizations should prioritize patch management and implement strict document validation policies to mitigate the risk, while also monitoring for potential exploitation attempts in their network traffic and endpoint detection systems.
The technical nature of this vulnerability stems from inadequate bounds checking within the PDF parsing logic, where the application fails to properly validate the size and structure of data elements before attempting to read them from memory. This type of memory safety issue is particularly prevalent in applications written in languages such as C or C++ where developers must manually manage memory allocation and deallocation. The vulnerability demonstrates the importance of robust input validation and defensive programming practices, especially in applications that process untrusted data from external sources. Security practitioners should implement network segmentation, email filtering, and endpoint protection measures to reduce the attack surface and prevent unauthorized access to systems that may be vulnerable to this type of exploitation. Regular security assessments and vulnerability scanning should include checks for this specific CVE to ensure that all affected systems are properly updated and patched against this known security flaw.