CVE-2018-4958 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
Adobe Acrobat and Reader applications contain a critical use-after-free vulnerability that affects multiple versions across different release cycles. This vulnerability stems from improper memory management where freed memory blocks are still referenced by subsequent operations, creating opportunities for attackers to manipulate program execution flow. The flaw exists within the handling of specific document objects and can be triggered through malformed PDF files or malicious content embedded in documents. When exploited, this vulnerability allows attackers to execute arbitrary code with the privileges of the current user, potentially leading to complete system compromise. The vulnerability is particularly dangerous because it operates at the application level where users frequently interact with PDF documents, making exploitation highly probable through social engineering or drive-by download scenarios.
The technical nature of this use-after-free vulnerability aligns with common software security weaknesses that fall under the CWE-416 category, which specifically addresses the use of freed memory. This weakness enables attackers to corrupt memory structures and redirect program execution through controlled data manipulation. The vulnerability can be exploited via the standard attack patterns described in the MITRE ATT&CK framework under the technique T1059.007 for command and scripting interpreter, where malicious code execution leads to further compromise. Attackers typically craft malicious PDF documents that, when opened by vulnerable applications, trigger the use-after-free condition in memory management routines. The exploitation process involves allocating memory, using it, freeing it, and then accessing the freed memory block through crafted input data that causes the application to behave unpredictably.
The operational impact of this vulnerability extends beyond simple code execution to encompass full system compromise capabilities. Once an attacker gains arbitrary code execution, they can install malware, steal sensitive information, modify system configurations, or establish persistence mechanisms. The vulnerability affects multiple versions of Adobe Reader and Acrobat, making it particularly widespread across enterprise environments where these applications are commonly deployed. Organizations using older versions of these applications face heightened risk due to the extended support periods for these vulnerable releases. The attack surface is broad since PDF documents are frequently shared via email, web downloads, and removable media, providing numerous vectors for exploitation. Security teams must consider this vulnerability as a critical threat requiring immediate remediation.
Mitigation strategies for this vulnerability must include immediate patching of affected applications to the latest versions provided by Adobe. Organizations should implement strict document validation policies and consider sandboxing PDF viewing applications to limit potential damage from exploitation attempts. Network-based security controls such as web application firewalls and content filtering solutions can help prevent the delivery of malicious PDF files to end users. Regular security assessments and vulnerability scanning should include checks for outdated Adobe Reader installations to prevent exploitation. Additionally, user education programs should emphasize the importance of only opening PDF documents from trusted sources and maintaining current software versions. System administrators should monitor for suspicious activity patterns that might indicate exploitation attempts and implement proper incident response procedures. The vulnerability highlights the importance of maintaining up-to-date security patches and demonstrates how seemingly minor memory management flaws can result in critical security breaches.