CVE-2017-2946 in Acrobat Reader
Summary
by MITRE
Adobe Acrobat Reader versions 15.020.20042 and earlier, 15.006.30244 and earlier, 11.0.18 and earlier have an exploitable heap overflow vulnerability when parsing the segment for storing non-graphic information. Successful exploitation could lead to arbitrary code execution.
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Analysis
by VulDB Data Team • 10/28/2022
Adobe Acrobat Reader contains a critical heap overflow vulnerability that exists in the parsing mechanism for handling segment data structures used to store non-graphic information within pdf documents. This vulnerability affects multiple version ranges including 15.020.20042 and earlier, 15.006.30244 and earlier, and 11.0.18 and earlier versions of the software. The flaw occurs when the application processes malformed segment data that exceeds the allocated heap buffer boundaries during the parsing of non-graphic information components within pdf files. This heap overflow condition creates an opportunity for attackers to execute arbitrary code on the target system through carefully crafted malicious pdf documents that trigger the vulnerable parsing routine. The vulnerability stems from inadequate bounds checking and memory management within the pdf parsing engine, specifically when handling segment descriptors that contain oversized data payloads. According to the CWE classification, this represents a classic heap-based buffer overflow vulnerability under CWE-121, which occurs when insufficient bounds checking allows data to overwrite adjacent memory locations. The attack vector typically involves social engineering techniques where users are tricked into opening malicious pdf files that contain specially crafted segment data designed to overflow the heap buffer. From an operational perspective, successful exploitation of this vulnerability could result in complete system compromise, allowing attackers to execute malicious code with the privileges of the victim user. The vulnerability aligns with ATT&CK technique T1203 - Exploitation for Client Execution, where adversaries leverage vulnerabilities in software applications to gain code execution. The impact extends beyond simple privilege escalation as attackers could potentially establish persistent access, exfiltrate sensitive data, or deploy additional malware. Organizations using affected versions of Adobe Acrobat Reader face significant risk exposure, particularly in environments where users frequently open pdf documents from untrusted sources. The vulnerability's exploitability is enhanced by the widespread use of Adobe Reader across enterprise environments and the common practice of opening pdf attachments from email communications. This makes the attack surface particularly broad and increases the likelihood of successful exploitation in targeted campaigns.
The technical implementation of this heap overflow occurs when the pdf parser attempts to process segment information that contains oversized data structures, leading to memory corruption in the heap allocation. The vulnerability is particularly concerning because it operates within the context of document parsing, which is a fundamental function of the application and occurs during normal user interaction. The heap overflow creates memory corruption that can be leveraged to overwrite critical memory structures, potentially allowing attackers to redirect program execution flow through return address manipulation or function pointer overwrites. Security researchers have identified that the vulnerability is most effectively exploited when the malicious payload is carefully crafted to align with the specific memory layout of the target system, making it particularly dangerous in environments where system memory patterns are predictable. The exploit development process involves creating pdf files with malformed segment data that causes the heap buffer to overflow, typically by sending more data than the allocated buffer can accommodate. This type of vulnerability is classified as a type of memory corruption vulnerability that can be exploited through various methods including stack pivoting and heap spraying techniques. The vulnerability demonstrates the importance of proper input validation and bounds checking in parsing applications, as the lack of such controls creates opportunities for attackers to manipulate program execution flow. Organizations should consider implementing additional security controls such as pdf sandboxing, restricted user privileges, and network segmentation to reduce the potential impact of successful exploitation. The vulnerability also highlights the need for regular security updates and patch management processes, as Adobe has released patches addressing this specific heap overflow condition in subsequent versions of Acrobat Reader.