CVE-2018-5017 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 stems from inadequate input validation within the document parsing functionality. This vulnerability falls under the Common Weakness Enumeration category CWE-129, which represents insufficient validation of length of input buffers, and more specifically aligns with CWE-787, representing out-of-bounds write or read conditions. The flaw occurs when the software processes malformed PDF files that contain specially crafted data structures, particularly within the document object model where array indices are not properly validated against array boundaries.
The technical exploitation of this vulnerability requires an attacker to craft a malicious PDF document that triggers an out-of-bounds memory access during the parsing process. When Adobe Reader or Acrobat attempts to read data from a memory location beyond the allocated buffer boundaries, the system may inadvertently expose sensitive information stored in adjacent memory regions. This information disclosure can include cryptographic keys, user credentials, system memory contents, or other confidential data that happens to be resident in the affected memory locations. The vulnerability is particularly dangerous because it can be triggered through simple document opening, requiring no special privileges or complex user interaction beyond viewing the malicious file.
The operational impact of this vulnerability extends beyond simple information disclosure, as the exposed memory contents could contain sensitive data that enables further attacks. Attackers could potentially leverage this information to reconstruct cryptographic keys, extract user session tokens, or gather system configuration details that aid in subsequent exploitation attempts. The vulnerability exists in multiple product versions, indicating a widespread issue that affects users across different Adobe Acrobat and Reader releases, making the potential attack surface extensive. This type of vulnerability is categorized under the ATT&CK technique T1059.007, which represents "Command and Scripting Interpreter: PowerShell," though in this case the initial access vector is through document parsing rather than command execution.
Mitigation strategies for this vulnerability include immediate deployment of Adobe's security patches and updates, which address the buffer validation issues by implementing proper bounds checking mechanisms. Organizations should also implement strict document filtering policies that prevent the opening of untrusted PDF files, particularly those received through email or downloaded from unverified sources. Network-based security solutions can be configured to scan PDF files for known malicious patterns, and users should be educated about the risks of opening suspicious documents. The vulnerability demonstrates the critical importance of maintaining up-to-date software versions and implementing defense-in-depth strategies that include both endpoint protection and network monitoring to detect and prevent exploitation attempts.