CVE-2016-6979 in Acrobat Reader
Summary
by MITRE
Use-after-free vulnerability in Adobe Reader and Acrobat before 11.0.18, Acrobat and Acrobat Reader DC Classic before 15.006.30243, and Acrobat and Acrobat Reader DC Continuous before 15.020.20039 on Windows and OS X allows attackers to execute arbitrary code via unspecified vectors, a different vulnerability than CVE-2016-1089, CVE-2016-1091, CVE-2016-6944, CVE-2016-6945, CVE-2016-6946, CVE-2016-6949, CVE-2016-6952, CVE-2016-6953, CVE-2016-6961, CVE-2016-6962, CVE-2016-6963, CVE-2016-6964, CVE-2016-6965, CVE-2016-6967, CVE-2016-6968, CVE-2016-6969, CVE-2016-6971, CVE-2016-6988, and CVE-2016-6993.
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Analysis
by VulDB Data Team • 10/18/2024
The CVE-2016-6979 vulnerability represents a critical use-after-free flaw affecting Adobe Reader and Acrobat products across multiple versions and operating systems. This vulnerability specifically impacts Adobe Reader versions prior to 11.0.18, Acrobat versions before 11.0.18, and various Adobe Acrobat Reader DC Classic and Continuous versions before their respective patched releases. The flaw manifests in both Windows and macOS environments, creating a widespread attack surface that security professionals must address immediately. The vulnerability's classification as a use-after-free issue indicates that the application attempts to access memory that has already been freed, a common but dangerous programming error that can lead to severe security consequences.
The technical implementation of this vulnerability involves memory management flaws that occur during the processing of specific file formats or operations within Adobe's PDF rendering engine. Attackers can exploit this condition by crafting malicious PDF files or manipulating existing documents in ways that trigger the problematic code path. When the application processes these specially crafted inputs, it frees memory associated with certain objects or data structures and subsequently attempts to access that same memory location, leading to potential code execution. This particular vulnerability operates through unspecified vectors, meaning the exact attack methodology remains partially obscured, but it's understood to involve memory corruption techniques that have been documented in similar Adobe vulnerabilities.
The operational impact of CVE-2016-6979 extends beyond simple privilege escalation or local code execution, as it enables attackers to gain complete system control when exploited successfully. The vulnerability's presence in widely deployed software like Adobe Reader creates significant risk for enterprise environments where users frequently open PDF documents from untrusted sources. Organizations using affected versions of Adobe Acrobat and Reader face potential compromise through spear-phishing campaigns, malicious document delivery, or supply chain attacks. The vulnerability's similarity to other CVEs in the same timeframe suggests that attackers may have developed exploit tooling that could be reused against this flaw, increasing the overall threat level. This type of vulnerability aligns with ATT&CK technique T1059.007 for command and scripting interpreter and CWE-416 for use after free, both of which represent common attack patterns in exploit development.
Mitigation strategies for CVE-2016-6979 should prioritize immediate patch deployment across all affected systems, as the vulnerability represents a high-severity threat requiring urgent attention. Organizations should implement application whitelisting policies to restrict execution of untrusted PDF files and consider deploying sandboxing solutions to isolate PDF processing activities. Network-level controls such as PDF content filtering and deep packet inspection can help detect and block malicious documents before they reach end-user systems. Security teams should also implement monitoring for suspicious file access patterns and memory corruption indicators that might suggest exploitation attempts. The vulnerability's classification as a use-after-free issue means that traditional antivirus solutions may not detect exploitation attempts, making behavioral monitoring and endpoint detection crucial components of any defense strategy. Regular security assessments and penetration testing should verify that patched systems remain secure against similar vulnerabilities in the broader Adobe ecosystem.