CVE-2018-15938 in Acrobat Reader
Summary
by MITRE
Adobe Acrobat and Reader versions 2018.011.20063 and earlier, 2017.011.30102 and earlier, and 2015.006.30452 and earlier have an out-of-bounds write vulnerability. Successful exploitation could lead to arbitrary code execution.
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Analysis
by VulDB Data Team • 05/25/2023
Adobe Acrobat and Reader applications contain a critical out-of-bounds write vulnerability that affects multiple product versions including 2018.011.20063 and earlier, 2017.011.30102 and earlier, and 2015.006.30452 and earlier. This vulnerability resides in the handling of specific file formats and occurs when the software processes malformed input data that exceeds allocated memory boundaries. The flaw represents a classic buffer overflow condition where an application writes data beyond the bounds of a pre-allocated memory buffer, potentially allowing attackers to overwrite adjacent memory locations. This type of vulnerability is categorized under CWE-787 Out-of-bounds Write as defined by the Common Weakness Enumeration framework, which specifically addresses situations where programs write to memory locations outside the intended buffer boundaries. The vulnerability is particularly dangerous because it can be exploited to execute arbitrary code on the target system, making it a prime candidate for remote code execution attacks. Attackers can craft malicious PDF files that trigger this vulnerability when opened by vulnerable versions of Adobe Acrobat or Reader, enabling them to gain unauthorized access to the system. The operational impact of this vulnerability extends beyond simple code execution, as it can lead to complete system compromise and persistent access. According to the MITRE ATT&CK framework, this vulnerability maps to T1059 Command and Scripting Interpreter and T1068 Exploitation for Privilege Escalation, as successful exploitation allows adversaries to execute malicious code and potentially escalate privileges. The attack surface is broad since PDF files are commonly shared and opened across various platforms, making this vulnerability particularly attractive to threat actors. The out-of-bounds write condition typically occurs during parsing operations when the application fails to properly validate input data length against allocated buffer sizes. This vulnerability is especially concerning because it affects multiple versions spanning several years, indicating a persistent flaw in the software's input validation mechanisms. The exploitation process requires careful crafting of malicious PDF content that can trigger the specific memory corruption scenario, typically involving malformed embedded objects or streams within the PDF structure. Security researchers have noted that the vulnerability is particularly difficult to detect through standard security scanning due to its reliance on specific parsing conditions that may not be immediately apparent. Organizations running affected versions of Adobe Acrobat and Reader should prioritize immediate remediation through official patches provided by Adobe, as the vulnerability can be exploited remotely without user interaction once a malicious PDF is opened. The risk assessment for this vulnerability is elevated due to its potential for automated exploitation and the widespread use of Adobe Reader across enterprise environments. Additional mitigations include implementing strict PDF file validation policies, restricting user access to PDF handling capabilities, and deploying network-based intrusion detection systems that can identify suspicious PDF content patterns. The vulnerability demonstrates the critical importance of proper input validation and memory management in software development, particularly for applications that process untrusted data from external sources. Organizations should also consider implementing sandboxing mechanisms for PDF processing and maintaining up-to-date threat intelligence to monitor for exploitation attempts targeting this specific vulnerability.