CVE-2015-6689 in Acrobat Reader
Summary
by MITRE
Use-after-free vulnerability in Adobe Reader and Acrobat 10.x before 10.1.16 and 11.x before 11.0.13, Acrobat and Acrobat Reader DC Classic before 2015.006.30094, and Acrobat and Acrobat Reader DC Continuous before 2015.009.20069 on Windows and OS X allows attackers to execute arbitrary code via a crafted WillSave document action, a different vulnerability than CVE-2015-5586, CVE-2015-6683, CVE-2015-6684, CVE-2015-6687, CVE-2015-6688, CVE-2015-6690, CVE-2015-6691, CVE-2015-7615, CVE-2015-7617, and CVE-2015-7621.
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Analysis
by VulDB Data Team • 06/21/2022
This vulnerability represents a critical use-after-free flaw in Adobe Acrobat and Reader products that enables remote code execution through malicious document manipulation. The vulnerability specifically affects versions prior to the mentioned patches across multiple product lines including the classic DC versions and various 10.x and 11.x releases. The flaw occurs when processing a crafted WillSave document action, which is a JavaScript event that triggers when a document is about to be saved. This particular attack vector differs from several other related vulnerabilities in the same timeframe, indicating a distinct code path within the application's document handling mechanism.
The technical nature of this vulnerability stems from improper memory management where freed memory blocks are still referenced after being deallocated. When Adobe Reader processes the malicious WillSave action, the application fails to properly validate or handle the document state, leading to a situation where memory that should have been released remains accessible to attackers. This creates an exploitable condition where malicious code can be injected into the application's memory space and executed with the privileges of the user running the software. The vulnerability is particularly dangerous because it allows attackers to execute arbitrary code without requiring user interaction beyond opening the malicious document, making it a prime target for zero-day exploits in targeted attacks.
The operational impact of CVE-2015-6689 extends beyond simple remote code execution to encompass potential full system compromise and privilege escalation scenarios. Attackers leveraging this vulnerability can gain unauthorized access to sensitive information, install malware, or establish persistent backdoors on affected systems. The vulnerability affects both Windows and OS X platforms, broadening its potential attack surface and making it particularly concerning for enterprise environments where multiple operating systems coexist. Organizations running affected versions of Adobe Reader and Acrobat are at significant risk, especially in environments where users frequently open documents from untrusted sources, which is common in email attachments and web downloads.
Security professionals should implement immediate mitigations including prompt patch deployment for all affected Adobe products, network segmentation to limit exposure, and enhanced email filtering to prevent delivery of malicious documents. The vulnerability aligns with CWE-416, which describes the use of freed memory conditions, and demonstrates patterns consistent with ATT&CK technique T1059.007 for command and scripting interpreter. Organizations should also consider implementing application whitelisting policies to restrict execution of untrusted PDF documents and deploy intrusion detection systems to monitor for exploitation attempts. Regular security assessments and vulnerability management programs should prioritize patching this vulnerability due to its high severity classification and documented exploitation in the wild. The distinct nature of this vulnerability compared to other CVEs in the same year indicates it may have been discovered independently, highlighting the importance of comprehensive security testing across all application components.