CVE-2016-1008 in Acrobat Reader
Summary
by MITRE
Untrusted search path vulnerability in Adobe Reader and Acrobat before 11.0.15, Acrobat and Acrobat Reader DC Classic before 15.006.30121, and Acrobat and Acrobat Reader DC Continuous before 15.010.20060 on Windows and OS X allows local users to gain privileges via a Trojan horse DLL in an unspecified directory.
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Analysis
by VulDB Data Team • 07/10/2022
This vulnerability represents a classic untrusted search path issue that affects multiple versions of Adobe Reader and Acrobat software across Windows and macOS platforms. The flaw stems from how these applications handle dynamic link library (dll) loading processes, creating opportunities for privilege escalation attacks. The vulnerability is categorized under CWE-427 which specifically addresses uncontrolled search path dependencies, making it a well-documented and dangerous class of software flaw that has been exploited in numerous security incidents over the years.
The technical implementation of this vulnerability allows local attackers to place malicious Trojan horse dll files in directories that are searched by Adobe applications during normal operation. When the vulnerable software attempts to load required libraries, it inadvertently executes the attacker-controlled code with elevated privileges. This occurs because the application's search path does not properly validate or sanitize the locations from which it loads dynamic libraries, particularly when these locations are not explicitly defined or controlled by the software vendor. The vulnerability affects both the traditional Acrobat and Reader installations as well as the newer DC Classic and Continuous versions, indicating a persistent issue in Adobe's library loading mechanisms.
The operational impact of this vulnerability is significant as it enables local users to escalate their privileges from standard user level to administrator level, depending on the target system configuration. Attackers can leverage this flaw to execute arbitrary code with elevated permissions, potentially leading to complete system compromise. The attack vector is particularly concerning because it requires minimal user interaction beyond the initial exploitation, as the malicious dll is loaded automatically when the vulnerable software is launched. This makes the vulnerability particularly attractive to threat actors who seek persistent access to target systems, as the privilege escalation can occur silently without user awareness.
Security professionals should implement multiple layers of defense to mitigate this vulnerability. The most effective immediate solution involves updating all affected Adobe products to their latest versions, as Adobe has released patches addressing this specific issue. Additionally, system administrators should consider implementing application whitelisting policies that restrict which dll files can be loaded by Adobe applications. The use of privilege separation techniques and ensuring that Adobe applications run with minimal required privileges can also reduce the potential impact of such attacks. Organizations should also monitor for suspicious dll files in common search paths and implement regular security audits to identify potential exploitation attempts. This vulnerability aligns with several tactics in the MITRE ATT&CK framework, particularly those related to privilege escalation and persistence mechanisms, making it a critical concern for enterprise security teams implementing comprehensive threat detection strategies.