CVE-2017-11211 in Acrobat Reader
Summary
by MITRE
Adobe Acrobat Reader 2017.009.20058 and earlier, 2017.008.30051 and earlier, 2015.006.30306 and earlier, and 11.0.20 and earlier has an exploitable heap overflow vulnerability in the JPEG parser. Successful exploitation could lead to arbitrary code execution.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 01/08/2021
Adobe Acrobat Reader contains a critical heap overflow vulnerability in its JPEG parser component that affects multiple versions including 2017.009.20058 and earlier, 2017.008.30051 and earlier, 2015.006.30306 and earlier, and 11.0.20 and earlier. This vulnerability falls under the CWE-121 heap-based buffer overflow category, where insufficient bounds checking allows maliciously crafted JPEG images to overwrite adjacent memory locations in the heap. The flaw occurs during the parsing of JPEG files when the application fails to properly validate the size of image data before copying it into fixed-size buffers, creating an exploitable condition that can be triggered through crafted input files. The vulnerability represents a significant security risk as it enables remote code execution when users open maliciously prepared PDF documents containing specially crafted JPEG images, making it particularly dangerous in phishing campaigns and targeted attacks. The heap overflow can be leveraged by attackers to overwrite critical memory structures including return addresses, function pointers, or other control data, potentially allowing arbitrary code execution with the privileges of the affected application. This vulnerability aligns with ATT&CK technique T1203 (Exploitation for Client Execution) and T1059 (Command and Scripting Interpreter) as it exploits application vulnerabilities to execute malicious code. The impact extends beyond simple privilege escalation since Adobe Acrobat Reader typically runs with elevated privileges when processing PDF documents, making successful exploitation particularly dangerous for end-user systems. Organizations using affected versions should immediately implement patch management procedures to upgrade to the latest versions of Adobe Acrobat Reader, as the vulnerability can be exploited remotely without user interaction, making it a prime target for automated exploit campaigns. The attack surface is broad due to the widespread use of Adobe Acrobat Reader across enterprise environments, and the vulnerability's exploitation requires minimal user interaction beyond opening a malicious document, making it highly effective for social engineering attacks.
The technical implementation of this vulnerability demonstrates poor input validation practices in the JPEG parsing library where the application does not properly check the boundaries of image data before copying it into internal buffers. When processing JPEG files, the parser reads image dimensions and data without adequate validation of the data size relative to the allocated buffer space, creating a condition where an attacker can craft a JPEG file that exceeds the buffer capacity. This overflow can be carefully constructed to overwrite specific memory locations, potentially redirecting program execution flow to malicious code. The vulnerability is particularly concerning because JPEG format is commonly used in PDF documents, and many users routinely open PDF files from untrusted sources. Security researchers have noted that the heap layout in Adobe Acrobat Reader makes this vulnerability particularly exploitable, as the overflow can be precisely controlled to overwrite function pointers or return addresses. The vulnerability affects both desktop and mobile versions of the software, with the attack vectors remaining consistent across platforms. Organizations should implement network-based protections including PDF file scanning, web application firewalls, and content filtering solutions to prevent exploitation attempts. The vulnerability also highlights the importance of keeping third-party libraries updated, as many of these applications rely on shared libraries for image processing that may contain similar vulnerabilities. Given the nature of the exploit, traditional antivirus solutions may not detect the malicious payload until after the vulnerability has been exploited, emphasizing the need for proactive patch management and application whitelisting solutions to prevent execution of vulnerable versions.