CVE-2017-2955 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 use after free vulnerability in the JavaScript engine. Successful exploitation could lead to arbitrary code execution.
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Analysis
by VulDB Data Team • 10/28/2022
The vulnerability identified as CVE-2017-2955 represents a critical use after free flaw within Adobe Acrobat Reader's JavaScript engine implementation. This vulnerability affects multiple versions of the software including 15.020.20042 and earlier, 15.006.30244 and earlier, and 11.0.18 and earlier releases. The issue stems from improper memory management practices within the JavaScript interpreter that processes PDF documents, creating conditions where freed memory locations can be accessed and reused by malicious code. Such flaws are particularly dangerous in document readers like Adobe Acrobat Reader because they can be triggered simply by opening a maliciously crafted PDF file, making them prime targets for remote exploitation.
The technical nature of this vulnerability places it squarely within the CWE-416 category of Use After Free conditions, which occur when a program continues to reference memory after it has been freed by the system. In Adobe Acrobat Reader's case, the JavaScript engine fails to properly track object lifecycles during script execution, allowing attackers to manipulate memory structures and potentially overwrite critical function pointers or execute arbitrary code. The exploitation process typically involves crafting a PDF document with malicious JavaScript that triggers the vulnerable code path, leading to memory corruption that can be leveraged for privilege escalation or complete system compromise. This vulnerability operates at the intersection of memory safety and script engine security, making it particularly challenging to defend against.
The operational impact of CVE-2017-2955 extends far beyond simple document rendering issues, as it enables attackers to achieve arbitrary code execution on vulnerable systems. This capability aligns with ATT&CK technique T1059.007 for JavaScript and T1068 for exploit development, representing a significant threat to enterprise environments where Adobe Acrobat Reader remains widely deployed. Organizations using affected versions face potential data breaches, system compromise, and lateral movement opportunities for threat actors. The vulnerability's exploitation requires minimal user interaction beyond opening a malicious document, making it particularly dangerous in targeted attack scenarios where social engineering can be minimized. Security teams must consider the broader implications of this vulnerability across their entire attack surface, as it can serve as an initial access vector for more sophisticated attacks.
Mitigation strategies for CVE-2017-2955 primarily focus on immediate remediation through software updates and patches provided by Adobe. Organizations should prioritize updating to versions of Adobe Acrobat Reader that address this specific vulnerability, as Adobe released security updates specifically targeting this use after free condition. Additional defensive measures include implementing PDF content filtering, disabling JavaScript execution in Acrobat Reader, and deploying network-based intrusion detection systems to monitor for exploitation attempts. The vulnerability also highlights the importance of maintaining up-to-date security patches across all software components, as it represents a classic example of how memory safety issues can be exploited in widely used applications. Organizations should also consider implementing application whitelisting policies and restricting user privileges when opening PDF documents to limit potential damage from successful exploitation attempts.