CVE-2017-16403 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. This vulnerability occurs as a result of a computation that reads data that is past the end of the target buffer; the computation is part of the image conversion module that processes Enhanced Metafile Format Plus (EMF+) data. The use of an invalid (out-of-range) pointer offset during access of internal data structure fields causes the vulnerability. A successful attack can lead to sensitive data exposure.
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Analysis
by VulDB Data Team • 09/03/2024
This vulnerability in Adobe Acrobat and Reader represents a classic buffer overread flaw that falls under the category of CWE-125, which describes out-of-bounds read conditions. The issue specifically affects multiple versions of Adobe's document processing software, including the 2017, 2015, and legacy 11.x series, making it a widespread concern across a significant portion of the user base. The vulnerability manifests within the image conversion module responsible for processing Enhanced Metafile Format Plus (EMF+) data, which is a vector commonly used in document embedding and graphics rendering.
The technical implementation of this flaw involves a computation that accesses memory beyond the intended buffer boundaries during EMF+ data processing. When the software attempts to read data past the end of the target buffer, it encounters an invalid pointer offset that references internal data structure fields. This type of memory access violation creates an exploitable condition where an attacker can manipulate the pointer arithmetic to access adjacent memory regions. The vulnerability is particularly concerning because it occurs during legitimate document processing operations, making it difficult to distinguish between benign and malicious content.
The operational impact of this vulnerability extends beyond simple data exposure, as it can potentially lead to information disclosure that may include sensitive system information, user data, or application memory contents. From an attack perspective, this vulnerability aligns with ATT&CK technique T1059.007 for command and scripting interpreter, as it could enable attackers to extract information that might be used for further exploitation. The flaw essentially allows for a form of information leakage that could provide attackers with insights into memory layout, application state, or other sensitive data that should remain protected within the application's memory space.
Mitigation strategies for this vulnerability should focus on immediate patch application, as Adobe has released updates addressing this specific issue. Organizations should prioritize updating all affected versions of Adobe Acrobat and Reader to the latest releases, particularly targeting the 2017.012.20098, 2017.011.30066, 2015.006.30355, and 11.0.22 versions mentioned in the vulnerability description. Additionally, implementing network-based protections through intrusion detection systems and monitoring for suspicious EMF+ file processing activities can help detect potential exploitation attempts. The vulnerability's nature as a buffer overread also suggests that input validation and bounds checking measures should be reinforced across all document processing modules, particularly those handling embedded graphics and metafile formats.