CVE-2017-16378 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 is due to a computation that accesses a pointer that has not been initialized; the computation occurs during internal AST thread manipulation. In this case, a computation defines a read from an unexpected memory location. Therefore, an attacker might be able to read sensitive portions of memory.
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Analysis
by VulDB Data Team • 01/24/2021
This vulnerability exists in 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 during internal abstract syntax tree thread manipulation operations where uninitialized pointer access occurs, creating a potential memory exposure condition. The technical implementation involves a computation that references a pointer without proper initialization, leading to unexpected memory reads from locations that should not be accessible to the current execution context. This type of vulnerability falls under the category of uninitialized pointer dereference, which is classified as CWE-476 in the Common Weakness Enumeration catalog. The vulnerability represents a classic memory safety issue where the application fails to properly validate pointer states before accessing memory locations, creating opportunities for information disclosure attacks.
The operational impact of this vulnerability extends beyond simple memory access violations as it provides attackers with the capability to read sensitive portions of memory that may contain confidential data, authentication tokens, or other critical information. When an attacker successfully exploits this vulnerability, they can potentially access memory regions that contain user data, system information, or application state details that should remain protected. This memory disclosure capability can be leveraged as a stepping stone for more sophisticated attacks, including privilege escalation or information gathering operations. The vulnerability's presence in multiple product versions indicates a systemic issue within the software's memory management implementation during thread manipulation processes, making it particularly concerning for widespread exploitation potential. From an attack framework perspective, this vulnerability aligns with techniques described in the ATT&CK methodology under the Information Gathering phase, where adversaries seek to extract sensitive information from compromised systems.
The exploitation of this vulnerability requires careful crafting of input data that triggers the specific AST thread manipulation path, typically involving malformed PDF files or specially constructed document elements that cause the application to process uninitialized pointers. Attackers may leverage this issue in targeted campaigns where they can influence the PDF processing flow to reach the vulnerable code path. Organizations should implement immediate mitigations including updating to patched versions of Adobe Acrobat and Reader, as well as deploying network-based protections such as PDF content filtering and sandboxing solutions. The vulnerability demonstrates the importance of proper pointer initialization and memory management practices in security-critical applications, particularly those handling untrusted input data. Security teams should also consider implementing monitoring for unusual memory access patterns and establish incident response procedures for potential exploitation attempts. Regular security assessments and code reviews focusing on memory safety practices can help prevent similar vulnerabilities in future software releases, emphasizing the need for comprehensive security testing throughout the software development lifecycle.