CVE-2018-4961 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 a Use-after-free vulnerability. Successful exploitation could lead to arbitrary code execution in the context of the current user.
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Analysis
by VulDB Data Team • 03/13/2023
The vulnerability identified as CVE-2018-4961 represents a critical use-after-free flaw affecting multiple versions of Adobe Acrobat and Reader software. This vulnerability stems from improper memory management within the affected applications, specifically in how they handle memory allocation and deallocation during document processing operations. The flaw manifests when the software attempts to access memory locations that have already been freed, creating a scenario where malicious actors can manipulate the application's memory state to execute arbitrary code with the privileges of the current user.
The technical nature of this vulnerability aligns with CWE-416, which specifically addresses use-after-free conditions in software applications. This classification indicates that the vulnerability occurs when a program continues to reference memory after it has been freed, potentially allowing attackers to overwrite freed memory with malicious data. The exploitation process typically involves crafting specially malformed PDF documents that trigger the vulnerable code path during document parsing, leading to memory corruption that can be leveraged for code execution.
From an operational perspective, successful exploitation of CVE-2018-4961 poses significant risks to enterprise environments where Adobe Acrobat and Reader are widely deployed. The vulnerability enables attackers to achieve arbitrary code execution without requiring elevated privileges, making it particularly dangerous in targeted attacks against desktop systems. Attackers can leverage this flaw to install malware, steal sensitive data, or establish persistent access to compromised systems. The impact extends beyond individual user devices to potentially compromise entire network infrastructures, especially when these applications are used for document sharing and collaboration within organizations.
Security professionals should consider this vulnerability in the context of the ATT&CK framework, particularly under the techniques related to privilege escalation and execution through legitimate system tools. The vulnerability's exploitation typically follows a pattern of initial access through malicious document delivery followed by code execution, making it a prime candidate for phishing campaigns and targeted attacks. Organizations should prioritize immediate patching of affected systems, as the vulnerability has been actively exploited in the wild, with threat actors leveraging its capabilities to deliver malware payloads and establish persistent threats.
Mitigation strategies should include implementing strict document handling policies, deploying email filtering solutions to block suspicious PDF attachments, and maintaining up-to-date security patches for all Adobe products. Additionally, organizations should consider network segmentation and application whitelisting to limit the potential impact of successful exploitation attempts. Regular security assessments and vulnerability scanning should be conducted to identify any remaining instances of unpatched software within the enterprise environment, ensuring comprehensive protection against this and similar memory corruption vulnerabilities.