CVE-2017-16392 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 buffer access with an incorrect length value in the JPEG processing module. Crafted input with an unexpected JPEG file segment size causes a mismatch between allocated buffer size and the access allowed by the computation. If an attacker can adequately control the accessible memory then this vulnerability can be leveraged to achieve arbitrary code execution.
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Analysis
by VulDB Data Team • 01/24/2021
The vulnerability identified as CVE-2017-16392 represents a critical buffer over-read condition affecting multiple versions of Adobe Acrobat and Reader software. This flaw resides within the JPEG processing module where improper handling of file segment sizes creates a scenario where allocated memory buffers do not match the actual data access requirements. The issue manifests when processing crafted JPEG files containing unexpected segment size values that cause the application to compute incorrect buffer boundaries during image parsing operations. This misalignment between allocated memory space and intended data access creates a predictable exploitation vector for malicious actors.
The technical implementation of this vulnerability falls under the category of buffer overflow conditions and more specifically aligns with CWE-121 which describes stack-based buffer overflow scenarios. The flaw operates through a classic buffer management error where the application allocates memory based on incorrect assumptions about input data size, leading to memory access violations that can be exploited for code execution. When an attacker controls the input JPEG data, they can manipulate segment size values to force the application into accessing memory regions beyond the originally allocated buffer boundaries, potentially allowing for arbitrary code execution within the application context.
From an operational perspective, this vulnerability poses significant risk to organizations relying on Adobe Acrobat and Reader for document processing and viewing. The exploitation requires minimal user interaction, typically through opening a maliciously crafted PDF file containing the specially formatted JPEG data. The attack surface extends across multiple product versions, making it particularly dangerous as organizations may have legacy systems running older vulnerable versions. Security researchers have noted that the vulnerability can be leveraged for privilege escalation attacks, potentially allowing attackers to execute malicious code with the privileges of the targeted user.
The exploitation of this vulnerability follows patterns consistent with the attack technique described in the MITRE ATT&CK framework under T1059 which covers command and scripting interpreter techniques. Attackers can leverage the buffer overflow to inject and execute malicious code within the application environment, potentially leading to full system compromise. The vulnerability's impact is amplified by the widespread use of Adobe Reader across enterprise environments, making it an attractive target for targeted attacks. Organizations should implement immediate mitigations including patching to the latest versions of Adobe Acrobat and Reader, network segmentation to limit access to vulnerable systems, and user education to avoid opening suspicious PDF attachments. Additionally, implementing application whitelisting policies and monitoring for unusual PDF processing activities can help detect potential exploitation attempts.