CVE-2015-7650 in Acrobat Reader
Summary
by MITRE
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 allow attackers to execute arbitrary code or cause a denial of service (out-of-bounds read and memory corruption) via a crafted CMAP table in a PDF document, a different vulnerability than CVE-2015-6685, CVE-2015-6686, CVE-2015-6693, CVE-2015-6694, CVE-2015-6695, and CVE-2015-7622.
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Analysis
by VulDB Data Team • 11/23/2024
Adobe Reader and Acrobat versions prior to specific patched releases contain a critical out-of-bounds read vulnerability within their PDF parsing functionality that can be exploited to execute arbitrary code or cause denial of service conditions. This vulnerability specifically affects the handling of CMAP tables within PDF documents, which are used for character mapping in font rendering processes. The flaw manifests when the application processes malformed CMAP data structures that exceed allocated memory boundaries during the parsing of PDF font dictionaries. The vulnerability is classified as a memory corruption issue that can lead to unpredictable behavior including application crashes, heap corruption, or potential code execution in the context of the vulnerable application.
The technical implementation of this vulnerability stems from insufficient input validation and boundary checking within Adobe's PDF parsing engine. When processing a specially crafted PDF document containing a malformed CMAP table, the application fails to properly validate array indices or buffer limits before accessing memory locations. This allows an attacker to craft a PDF file with carefully constructed CMAP data that triggers an out-of-bounds memory read operation. The vulnerability resides in the font handling subsystem and is particularly dangerous because it can be triggered through normal PDF document rendering operations without requiring special privileges or user interaction beyond opening the malicious document. This type of vulnerability aligns with CWE-129, which describes improper validation of array indices, and represents a classic memory safety issue that enables privilege escalation and remote code execution scenarios.
The operational impact of this vulnerability extends across multiple Adobe products and platforms, affecting Windows and OS X operating systems with various versions of Acrobat and Reader. Attackers can leverage this flaw to achieve arbitrary code execution on targeted systems, potentially leading to complete system compromise. The vulnerability is particularly concerning because it can be delivered through email attachments, web downloads, or other common attack vectors where users might open PDF documents. The memory corruption aspect makes exploitation more reliable than simple buffer overflow conditions, as it can trigger consistent crashes or more sophisticated attack patterns. This vulnerability demonstrates the ongoing challenges in securing complex document processing engines and highlights the importance of proper input validation in security-critical applications. The flaw's classification as a remote code execution vulnerability places it in the ATT&CK framework under the technique of "Exploitation for Client Execution" and represents a significant risk to enterprise environments where PDF documents are commonly shared and opened.
Organizations should immediately deploy patches provided by Adobe to address this vulnerability, as the risk of exploitation in the wild is substantial. System administrators should implement network-based protections including PDF file filtering and sandboxing techniques to reduce the attack surface. The vulnerability's nature suggests that attackers may develop exploit code quickly, making immediate remediation essential. Additional mitigations include disabling PDF preview features in web browsers, implementing strict file type validation, and conducting regular security assessments of document handling systems. Security teams should monitor for indicators of compromise related to PDF-based attacks and maintain updated threat intelligence regarding similar vulnerabilities in Adobe products. The vulnerability demonstrates the critical importance of keeping third-party applications updated and implementing layered security approaches to protect against document-based attack vectors that target the core rendering engines of widely used software applications.