CVE-2017-16415 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 a part of the functionality that handles font encodings. The vulnerability is a result of 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 resides within Adobe Acrobat and Reader software across multiple version ranges including 2017.012.20098 and earlier, 2017.011.30066 and earlier, 2015.006.30355 and earlier, and 11.0.22 and earlier versions. The flaw manifests in the font encoding handling functionality where a buffer overflow occurs due to improper bounds checking during data processing. This represents a classic out-of-bounds memory access vulnerability that falls under the CWE-121 category of buffer overflow conditions. The vulnerability specifically involves an out-of-range pointer offset used to access internal data structure elements, creating a situation where memory beyond the intended buffer boundaries gets accessed and potentially modified.
The technical implementation of this vulnerability stems from improper validation of font encoding data structures during processing. When Adobe Acrobat or Reader encounters font data, it performs computations to determine memory offsets for accessing sub-elements within internal data structures. These computations fail to properly validate boundary conditions, allowing an attacker to craft malicious font data that causes the application to write beyond allocated buffer limits. This type of memory corruption can lead to unpredictable behavior including application crashes, data corruption, or more critically, arbitrary code execution. The vulnerability operates at the intersection of memory management and input validation, representing a fundamental flaw in how the software handles external font data.
From an operational perspective, this vulnerability poses significant risk to organizations relying on Adobe Acrobat and Reader for document processing. Attackers can exploit this weakness by embedding malicious font data within PDF documents, which when opened by vulnerable software versions can trigger the buffer overflow condition. The attack vector requires user interaction through opening a malicious document, making it a typical social engineering target. Successful exploitation could result in complete system compromise, data theft, or deployment of additional malware. The vulnerability's impact is amplified by the widespread use of Adobe Reader across enterprise environments, where a single compromised document could potentially affect multiple users. This aligns with ATT&CK technique T1203 which involves exploitation of software vulnerabilities for privilege escalation and system control.
The recommended mitigation strategy involves immediate patching of all affected Adobe Acrobat and Reader versions to the latest available security updates from Adobe. Organizations should also implement strict document validation policies, including sandboxing PDF processing environments and restricting font embedding in critical document workflows. Network-level controls such as web application firewalls and content filtering systems can help prevent the delivery of malicious PDF documents. Additionally, user education regarding suspicious document attachments and enabling automatic updates for Adobe software can significantly reduce exploitation risk. Regular security assessments and vulnerability scanning should be conducted to identify any remaining unpatched systems. The vulnerability demonstrates the critical importance of proper input validation and memory management practices in preventing remote code execution exploits.