CVE-2018-4903 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 the 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-2018-4903 represents a critical buffer overflow condition affecting Adobe Acrobat Reader across multiple version ranges including 2018.009.20050 and earlier, 2017.011.30070 and earlier, and 2015.006.30394 and earlier. This flaw manifests within the TIFF processing functionality that operates within the XPS module of the software, creating a scenario where memory access extends beyond the bounds of allocated buffer regions. The underlying issue stems from improper boundary checking during the processing of TIFF image files embedded within XPS documents, which allows for arbitrary memory reads that can potentially expose sensitive information stored in adjacent memory locations.
The technical nature of this vulnerability aligns with CWE-125, which describes "Out-of-bounds Read" conditions where programs access memory locations beyond the intended buffer boundaries. This particular implementation flaw occurs when the XPS module processes TIFF formatted images, specifically during the parsing and rendering operations that involve buffer computations. The vulnerability exploits the lack of proper input validation and boundary checking mechanisms, enabling attackers to manipulate the processing flow and cause the application to read memory locations that should remain protected or inaccessible. The attack vector requires an attacker to craft a malicious XPS document containing specially formatted TIFF data that triggers the vulnerable code path.
From an operational perspective, this vulnerability poses significant risks to organizations that rely on Adobe Acrobat Reader for document processing and viewing. The successful exploitation of CVE-2018-4903 could result in information disclosure attacks where sensitive data from memory locations adjacent to the targeted buffer becomes accessible to unauthorized parties. This exposure could potentially include user credentials, session tokens, application configuration details, or other confidential information stored in memory. The vulnerability's impact is amplified by the widespread use of Adobe Acrobat Reader across enterprise environments, making it an attractive target for threat actors seeking to gain unauthorized access to sensitive information. The attack requires minimal user interaction beyond opening a malicious document, making it particularly dangerous in targeted phishing campaigns or supply chain attacks.
Security mitigations for CVE-2018-4903 should prioritize immediate patch deployment from Adobe, as the vendor has released updates addressing this specific buffer overflow condition. Organizations should implement network-level controls to prevent the execution of potentially malicious XPS documents, particularly those originating from untrusted sources. The remediation process should include comprehensive testing of the patched versions to ensure that the buffer overflow protections are properly implemented without introducing regressions in functionality. Additionally, security teams should consider implementing application whitelisting policies that restrict the execution of Adobe Acrobat Reader to trusted environments and monitor for any suspicious document processing activities. The vulnerability demonstrates the importance of maintaining up-to-date software versions and implementing robust input validation mechanisms across all document processing components to prevent similar buffer overflow conditions from being exploited in the future.