CVE-2018-4986 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 stems from improper input validation within the document processing engine that fails to properly bounds-check array accesses when parsing maliciously crafted pdf files. The flaw exists in the way the software handles certain embedded objects and streams within pdf documents, specifically when processing font data and embedded javascript code. When a malicious pdf file is opened, the application attempts to read memory locations beyond the allocated buffer boundaries, potentially exposing sensitive data from adjacent memory regions. This type of vulnerability falls under CWE-129, which specifically addresses insufficient bounds checking, and represents a classic example of memory safety issues that can lead to information disclosure attacks. The out-of-bounds read occurs during the parsing of pdf objects where the application does not validate the length of data structures before attempting to access array elements. Attackers can exploit this by crafting specially formatted pdf documents that trigger the vulnerable code path when opened by an affected version of Adobe Reader or Acrobat. The operational impact extends beyond simple information disclosure as this vulnerability could potentially be leveraged in combination with other techniques to achieve remote code execution or privilege escalation. The vulnerability affects not only end-user systems but also enterprise environments where these applications are widely deployed, making it particularly dangerous in targeted attack scenarios. Organizations running affected versions of Adobe Acrobat and Reader should immediately implement mitigations such as disabling javascript execution, implementing strict pdf file validation policies, and applying the latest security patches from Adobe. The ATT&CK framework categorizes this vulnerability under T1059 for command and scripting interpreter and T1068 for exploit for privilege escalation, highlighting the potential for further compromise once initial access is achieved through this vulnerability. This weakness is particularly concerning because it requires no user interaction beyond opening a malicious document, making it suitable for drive-by download attacks. The vulnerability demonstrates the importance of proper input validation and memory safety practices in document processing applications, as these tools must handle untrusted content from various sources without compromising system security. Security professionals should monitor for exploitation attempts and implement network-based detection measures to identify potential malicious pdf files targeting this specific vulnerability.