CVE-2018-4905 in Acrobat Reader
Summary
by MITRE
An issue was discovered in Adobe Acrobat Reader 2018.009.20050 and earlier versions, 2017.011.30070 and earlier versions, 2015.006.30394 and earlier versions. This vulnerability occurs as a result of computation that reads data that is past the end of the target buffer; the computation is part of TIFF processing within the XPS module. A successful attack can lead to sensitive data exposure.
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Analysis
by VulDB Data Team • 02/10/2023
The vulnerability identified as CVE-2018-4905 represents a critical buffer over-read condition affecting Adobe Acrobat Reader across multiple version lines including 2018.009.20050 and earlier, 2017.011.30070 and earlier, and 2015.006.30394 and earlier. This flaw exists within the TIFF processing functionality that operates within the XPS module of the software, creating a scenario where the application attempts to read memory locations beyond the boundaries of allocated buffer space. The vulnerability stems from inadequate bounds checking during image processing operations, specifically when handling TIFF formatted images embedded within XPS documents. This type of vulnerability falls under CWE-125, which categorizes out-of-bounds read conditions as a fundamental memory safety issue that can lead to information disclosure and potentially more severe exploitation vectors.
The technical execution of this vulnerability occurs when a maliciously crafted XPS document containing specially formatted TIFF images is opened within Adobe Acrobat Reader. During the processing of these images, the application's TIFF parser fails to properly validate the boundaries of image data structures, leading to a situation where memory reads extend beyond the intended buffer limits. This over-read behavior can expose sensitive information stored in adjacent memory locations, potentially including stack contents, heap data, or other application memory segments that may contain credentials, session tokens, or other confidential data. The vulnerability is particularly concerning because it operates within the context of document rendering, making it easily exploitable through social engineering tactics where users are tricked into opening malicious documents.
From an operational impact perspective, this vulnerability creates significant security risks for organizations relying on Adobe Acrobat Reader for document handling. The exposure of sensitive data through memory reads can compromise user credentials, system information, and potentially confidential business data that may be stored in memory during document processing. The attack vector is relatively simple and can be executed through email attachments, web downloads, or file sharing platforms where users unknowingly open compromised XPS documents. This vulnerability aligns with ATT&CK technique T1059.007, which covers the use of application-specific commands, and T1566.001, covering spearphishing attachments. The low complexity of exploitation combined with the potential for information disclosure makes this vulnerability particularly dangerous in enterprise environments where document sharing is common.
Organizations should implement immediate mitigations including urgent patching of Adobe Acrobat Reader installations to versions that address this buffer over-read condition. System administrators should also consider implementing email filtering rules that block suspicious XPS and TIFF document attachments, particularly from untrusted sources. Network-based intrusion detection systems can be configured to monitor for anomalous document processing patterns that may indicate exploitation attempts. Additionally, user education programs should emphasize the importance of verifying document sources before opening attachments, especially those containing embedded image formats. The vulnerability demonstrates the importance of proper input validation and bounds checking in image processing libraries, and organizations should review their document handling workflows to minimize exposure to similar issues in other software components. Regular security assessments of document processing capabilities and memory safety practices should be conducted to identify and remediate similar vulnerabilities before they can be exploited by adversaries.