CVE-2018-4962 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 an Out-of-bounds read vulnerability. Successful exploitation could lead to information disclosure.
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Analysis
by VulDB Data Team • 07/21/2024
Adobe Acrobat and Reader applications contain a critical out-of-bounds read vulnerability that affects multiple version ranges including 2018.011.20038 and earlier, 2017.011.30079 and earlier, and 2015.006.30417 and earlier. This vulnerability falls under the CWE-129 weakness category, which specifically addresses improper validation of array index values, and represents a classic buffer over-read condition that can be exploited by malicious actors. The flaw occurs when the applications process specially crafted pdf files that contain malformed data structures, leading to memory access violations beyond the bounds of allocated buffers. This particular vulnerability stems from inadequate input validation mechanisms within the pdf parsing components, particularly in how the software handles array indexing during document rendering processes. The out-of-bounds read condition allows attackers to potentially read sensitive memory contents that may contain confidential information, user credentials, or system data, making this a significant information disclosure risk. When exploited, the vulnerability can result in unauthorized data exposure through memory dumps or by accessing adjacent memory regions that contain valuable information. The attack vector typically involves tricking users into opening maliciously crafted pdf documents, which then triggers the vulnerable code path during document parsing or rendering operations. This vulnerability aligns with ATT&CK technique T1059.007 for command and scripting interpreter, specifically through the use of pdf-based attack delivery methods, and represents a common entry point for initial access in targeted attacks against enterprise environments. The impact of successful exploitation extends beyond simple information disclosure, as the leaked memory contents could potentially reveal encryption keys, user session data, or other sensitive system information that could be leveraged for further attacks.
The technical implementation of this vulnerability demonstrates a fundamental flaw in input sanitization and memory management practices within Adobe's pdf processing libraries. The out-of-bounds read occurs when the application fails to properly validate the length of arrays or buffers before accessing specific indices, allowing attackers to craft pdf files that contain malicious array specifications. This type of vulnerability is particularly dangerous because it can be triggered through legitimate user interactions with pdf documents, making it difficult to detect and prevent through traditional network-based security measures. The vulnerability's exploitation requires minimal privileges and can be executed through social engineering techniques that convince users to open malicious pdf attachments. Security researchers have identified that the flaw exists in the core pdf parsing engine where the software does not adequately check array bounds before accessing elements, creating a window of opportunity for attackers to manipulate memory access patterns. The vulnerability's presence across multiple version lines indicates a systemic issue within Adobe's codebase that affects long-term support releases, making the attack surface particularly broad and challenging to remediate. Organizations using these vulnerable versions face significant risk exposure, as the vulnerability can be exploited through various attack vectors including email attachments, web downloads, and file sharing platforms.
Organizations should implement immediate mitigations including mandatory software updates to the latest available versions of Adobe Acrobat and Reader, as Adobe has released patches to address this vulnerability. The recommended approach involves deploying automated patch management systems to ensure all endpoints receive security updates promptly, particularly in enterprise environments where multiple versions may be in use. Network-based security controls such as pdf content filtering and sandboxing solutions should be implemented to provide additional layers of protection against malicious pdf files. Security teams should also conduct comprehensive vulnerability assessments to identify all systems running vulnerable versions of Adobe software and prioritize remediation efforts accordingly. The implementation of user education programs is essential to reduce the risk of successful social engineering attacks that exploit this vulnerability through malicious pdf attachments. Regular security monitoring and incident response procedures should be enhanced to detect potential exploitation attempts, including monitoring for unusual memory access patterns or suspicious pdf processing activities. Organizations should also consider implementing application whitelisting policies that restrict execution of pdf files from untrusted sources and establish strict controls over document handling processes. The vulnerability's classification as a medium to high severity risk according to common vulnerability scoring systems indicates that immediate action is required to prevent potential exploitation, as the information disclosure capabilities could provide attackers with sufficient data to launch more sophisticated attacks. System administrators should also review and update their security policies to address the specific threat landscape associated with pdf-based attacks and ensure that appropriate security controls are in place to protect against similar vulnerabilities in the future.