CVE-2015-6693 in Acrobat Reader
Summary
by MITRE
The signatureSetSeedValue method in Adobe Reader and Acrobat 10.x before 10.1.16 and 11.x before 11.0.13, Acrobat and Acrobat Reader DC Classic before 2015.006.30094, and Acrobat and Acrobat Reader DC Continuous before 2015.009.20069 on Windows and OS X allows attackers to execute arbitrary code or cause a denial of service (memory corruption) via crafted arguments, a different vulnerability than CVE-2015-6685, CVE-2015-6686, CVE-2015-6694, CVE-2015-6695, and CVE-2015-7622.
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Analysis
by VulDB Data Team • 06/21/2022
The vulnerability identified as CVE-2015-6693 represents a critical memory corruption flaw within Adobe Reader and Acrobat software across multiple versions, specifically affecting the signatureSetSeedValue method implementation. This vulnerability exists in Adobe Reader and Acrobat 10.x versions prior to 10.1.16 and 11.x versions prior to 11.0.13, alongside the DC Classic and Continuous editions before their respective patch releases. The flaw manifests when the software processes crafted arguments through the signatureSetSeedValue method, creating a pathway for attackers to exploit memory corruption issues that can result in arbitrary code execution or denial of service conditions. The vulnerability operates independently from other related flaws such as CVE-2015-6685, CVE-2015-6686, CVE-2015-6694, CVE-2015-6695, and CVE-2015-7622, indicating a distinct code path within the software's signature handling mechanisms. This issue affects both Windows and OS X operating systems, demonstrating the cross-platform nature of the vulnerability within Adobe's PDF processing framework.
The technical exploitation of CVE-2015-6693 occurs when malicious input parameters are passed to the signatureSetSeedValue method, which lacks proper validation mechanisms for handling crafted arguments. This weakness creates a buffer overflow or memory corruption scenario that can be leveraged by attackers to execute arbitrary code with the privileges of the running process. The vulnerability's impact extends beyond simple code execution to include potential denial of service conditions, where the memory corruption can cause the application to crash or become unresponsive. The flaw resides in how the software manages memory allocation and argument processing within the signature handling component, making it particularly dangerous as PDF documents are frequently encountered in enterprise and personal computing environments. The method's insufficient input validation allows attackers to manipulate memory structures, potentially leading to privilege escalation or system compromise. According to CWE classification, this vulnerability maps to CWE-121, which describes heap-based buffer overflow conditions, and CWE-125, which addresses out-of-bounds read errors that can occur when processing malformed input data.
The operational impact of CVE-2015-6693 is significant within enterprise security environments where Adobe Reader and Acrobat are widely deployed for document processing and digital signature verification. Attackers can leverage this vulnerability through malicious PDF documents delivered via email, web downloads, or compromised websites, making it particularly dangerous in phishing campaigns or targeted attacks. The vulnerability's ability to cause memory corruption and arbitrary code execution means that successful exploitation can lead to complete system compromise, especially when users open malicious documents with elevated privileges. Organizations running affected versions of Adobe software face potential data breaches, system infiltration, and unauthorized access to sensitive information. The vulnerability's presence in both Reader and Acrobat products creates a broad attack surface, as these applications are commonly used for processing signed documents, making them prime targets for exploitation. The memory corruption nature of the flaw also means that system stability can be compromised, leading to unexpected application crashes and potential denial of service conditions that disrupt business operations. This vulnerability aligns with ATT&CK technique T1059.007, which covers the use of scripting languages for execution, as attackers may leverage the memory corruption to establish persistent access through malicious scripts or payloads.
Organizations should prioritize immediate patching of all affected Adobe Reader and Acrobat versions to mitigate CVE-2015-6693 exposure. Adobe released updates for all supported versions, including 10.1.16, 11.0.13, and their respective DC Classic and Continuous editions, which address the memory corruption issue through improved input validation and memory management. System administrators should implement comprehensive patch management procedures to ensure all endpoints running Adobe software are updated promptly. Additional mitigations include implementing Adobe Acrobat Reader sandboxing features, restricting PDF document handling through email security solutions, and monitoring for suspicious PDF file activity. Network security controls such as web proxies and content filtering systems should be configured to block or scan PDF documents from untrusted sources. The vulnerability's exploitation requires user interaction through opening malicious documents, making user education and awareness programs essential components of the overall security strategy. Organizations should also consider deploying endpoint protection solutions that can detect anomalous behavior patterns associated with memory corruption exploits. Regular security assessments and vulnerability scanning should include verification of Adobe software versions to ensure compliance with security baselines and prevent exploitation of known vulnerabilities.