CVE-2017-2109 in KUNAI
Summary
by MITRE
Cybozu KUNAI for Android 3.0.4 to 3.0.5.1 allow remote attackers to obtain log information through a malicious Android application.
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Analysis
by VulDB Data Team • 12/21/2020
The vulnerability identified as CVE-2017-2109 affects Cybozu KUNAI for Android versions 3.0.4 through 3.0.5.1, representing a critical security flaw that enables remote attackers to extract sensitive log information from affected devices. This vulnerability resides within the application's improper handling of log data and its exposure to malicious third-party applications. The flaw stems from inadequate access controls and insufficient sanitization of log files that contain potentially sensitive operational data, user activities, and system information. Attackers can exploit this weakness by installing a malicious Android application that leverages the compromised log access mechanisms to gather confidential information.
The technical implementation of this vulnerability involves the application's failure to properly secure its logging infrastructure against unauthorized access attempts. Specifically, the vulnerability manifests when the KUNAI application creates log files that are accessible to other applications without proper authentication or authorization checks. This design flaw allows malicious actors to craft applications that can read and extract log data from the targeted system, potentially exposing user credentials, session information, navigation patterns, and other sensitive operational details. The vulnerability operates at the application-level security boundary, where proper isolation between applications should be maintained but fails to function correctly.
From an operational perspective, this vulnerability poses significant risks to organizations and individual users who rely on Cybozu KUNAI for Android for business or personal activities. The exposure of log information can lead to comprehensive user profiling, session hijacking opportunities, and potential credential compromise. Attackers can utilize the extracted log data to conduct advanced persistent threat operations, perform social engineering attacks, or establish more sophisticated exploitation chains. The impact extends beyond simple information disclosure as the collected logs may contain timestamps, device identifiers, application usage patterns, and other metadata that can be correlated to build detailed attack profiles.
The vulnerability aligns with CWE-200, which addresses "Information Exposure," and demonstrates characteristics consistent with CWE-352, "Cross-Site Request Forgery," and CWE-284, "Improper Access Control." These mappings reflect the fundamental security weaknesses present in the application's architecture and access control mechanisms. The vulnerability also corresponds to ATT&CK techniques including T1074, "Data Staged," and T1005, "Data from Local System," which describe methods attackers use to collect and extract sensitive information from compromised systems. The attack vector follows the pattern of privilege escalation through application-level access control bypasses, where the malicious application leverages legitimate access points to gather information that should remain protected.
Organizations should immediately implement mitigations including updating to patched versions of Cybozu KUNAI for Android, implementing network monitoring to detect unusual access patterns, and conducting comprehensive security assessments of their mobile device management policies. The recommended approach involves strengthening access controls, implementing proper log file permissions, and establishing network segmentation to limit potential attack surfaces. Additionally, security teams should monitor for malicious applications in app stores and implement mobile threat defense solutions that can detect and prevent unauthorized log access attempts. Regular security awareness training for users about the risks of installing untrusted applications remains essential in mitigating exploitation opportunities.