CVE-2017-16416 in Acrobat Reader
Summary
by MITRE
An issue was discovered in Adobe Acrobat and Reader: 2017.012.20098 and earlier versions, 2017.011.30066 and earlier versions, 2015.006.30355 and earlier versions, and 11.0.22 and earlier versions. The vulnerability is caused by a computation that writes data past the end of the intended buffer; the computation is part of the image conversion module that handles Enhanced Metafile Format Plus (EMF+) data. The vulnerability is a result of an out of range pointer offset that is used to access sub-elements of an internal data structure. An attacker can potentially leverage the vulnerability to corrupt sensitive data or execute arbitrary code.
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Analysis
by VulDB Data Team • 09/04/2024
This vulnerability exists in Adobe Acrobat and Reader applications across multiple version ranges, specifically affecting versions up to 2017.012.20098, 2017.011.30066, 2015.006.30355, and 11.0.22. The flaw resides within the image conversion module responsible for processing Enhanced Metafile Format Plus (EMF+) data, representing a classic buffer overflow condition that allows for memory corruption. The vulnerability stems from an out-of-range pointer offset used to access internal data structure elements, creating a situation where computations write data beyond the intended buffer boundaries. This type of flaw falls under CWE-121, which describes stack-based buffer overflow conditions, and more specifically aligns with CWE-787, representing out-of-bounds write vulnerabilities. The operational impact of this vulnerability extends beyond simple data corruption, as it provides potential attack vectors for arbitrary code execution, making it particularly dangerous in targeted exploitation scenarios.
The technical exploitation of this vulnerability occurs when the image conversion module processes maliciously crafted EMF+ formatted data, causing the application to access memory locations beyond allocated buffer boundaries. This memory corruption can result in unpredictable application behavior, including crashes, data corruption, or more critically, the execution of attacker-controlled code within the application context. The flaw represents a significant risk because EMF+ files are commonly used in various document formats and can be embedded within PDF documents, making the attack surface broader than typical file format vulnerabilities. Attackers can leverage this vulnerability by crafting specially formatted EMF+ data that triggers the buffer overflow condition during normal document processing operations, potentially leading to complete system compromise through privilege escalation or code injection techniques.
From a cybersecurity perspective, this vulnerability aligns with several ATT&CK tactics including execution through malicious document attachments and privilege escalation. The attack chain typically involves delivering a malicious PDF document containing crafted EMF+ data to an unsuspecting user, who then opens the document with vulnerable Adobe Reader or Acrobat software. The vulnerability's classification as a heap-based or stack-based buffer overflow places it within the category of memory safety issues that have historically been primary targets for exploit development. Organizations should prioritize patching affected versions and implement content filtering measures to prevent execution of potentially malicious EMF+ data. Additionally, user education regarding document attachment handling and application sandboxing techniques can provide additional defensive layers against exploitation attempts. The vulnerability demonstrates the ongoing challenge of maintaining memory safety in complex multimedia processing libraries and highlights the importance of regular security updates in enterprise environments.