CVE-2017-3122 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 memory corruption vulnerability in the image conversion engine when processing Enhanced Metafile Format (EMF) data related to Bezier curves. Successful exploitation could lead to arbitrary code execution.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 01/08/2021
Adobe Acrobat Reader contains a critical memory corruption vulnerability that affects multiple versions including 2017.009.20058 and earlier, 2017.008.30051 and earlier, 2015.006.3030306 and earlier, and 11.0.20 and earlier. This vulnerability exists within the image conversion engine specifically when processing Enhanced Metafile Format EMF data that contains Bezier curve elements. The flaw manifests as an exploitable memory corruption issue that occurs during the parsing and rendering of EMF files, particularly when dealing with complex mathematical curve representations used in vector graphics. The vulnerability stems from inadequate bounds checking and memory management within the EMF processing module, which fails to properly validate the structure and size of Bezier curve data during conversion operations. This weakness allows attackers to craft malicious EMF files that trigger buffer overflows or other memory corruption conditions when the vulnerable software attempts to render these graphics elements. The attack vector requires the user to open a specially crafted EMF file within Adobe Acrobat Reader, making this a classic client-side exploitation scenario that leverages social engineering techniques to deliver malicious payloads. The vulnerability maps to CWE-121 heap-based buffer overflow and aligns with ATT&CK technique T1203, where adversaries exploit software vulnerabilities to execute arbitrary code on targeted systems. When successfully exploited, this vulnerability provides attackers with the ability to execute arbitrary code with the privileges of the user running the vulnerable software, potentially leading to complete system compromise and persistent access. The memory corruption occurs during the image conversion process when the software attempts to calculate and render Bezier curves, where insufficient input validation leads to memory corruption that can be leveraged for code execution. This represents a significant risk to enterprise environments where users may inadvertently open malicious documents, particularly in phishing campaigns or supply chain attacks. The vulnerability affects not only the latest versions of Adobe Reader but also older releases that remain in use within many organizations, creating a broad attack surface that extends across multiple product generations. Organizations should prioritize patching all affected versions and implement additional security controls such as email filtering, web application firewalls, and user education to mitigate the risk of exploitation. The remediation process requires immediate deployment of Adobe's security patches and potentially implementing network segmentation to limit the impact of successful exploitation attempts. Security teams should also monitor for indicators of compromise related to this vulnerability and consider implementing application whitelisting policies to prevent execution of untrusted EMF files. The vulnerability demonstrates the ongoing challenge of maintaining secure software in legacy systems where older versions continue to operate in enterprise environments despite known security risks.