CVE-2016-1156 in LINE
Summary
by MITRE
LINE 4.3.0.724 and earlier on Windows and 4.3.1 and earlier on OS X allows remote authenticated users to cause a denial of service (application crash) via a crafted post that is mishandled when displaying a Timeline.
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Analysis
by VulDB Data Team • 08/06/2018
The vulnerability identified as CVE-2016-1156 represents a denial of service flaw affecting LINE messaging applications across both Windows and macOS platforms. This issue specifically impacts versions 4.3.0.724 and earlier on Windows systems, and versions 4.3.1 and earlier on OS X operating systems. The vulnerability arises from improper handling of crafted post content during timeline display operations, creating a condition where authenticated remote attackers can trigger application instability. The flaw demonstrates characteristics consistent with memory corruption vulnerabilities and improper input validation issues that fall under CWE-20, which addresses "Improper Input Validation" in software security implementations. Such vulnerabilities represent significant risks in messaging applications where users frequently interact with content from untrusted sources, creating opportunities for exploitation through social engineering or compromised accounts.
The technical exploitation of this vulnerability occurs when a malicious user crafts a specially formatted post that, upon being displayed within the application's timeline feature, causes the LINE client to crash or become unresponsive. This occurs during the rendering process where the application fails to properly validate or sanitize incoming post data before attempting to display it. The improper handling suggests that the application lacks adequate bounds checking or input sanitization mechanisms when processing user-generated content. From an operational perspective, this vulnerability enables attackers to disrupt service availability for legitimate users, effectively creating a denial of service condition that impacts the core functionality of the messaging platform. The fact that this requires authentication indicates that the attack vector involves compromised accounts or insider threats rather than unauthenticated attacks, though the impact remains significant for service availability and user experience.
The operational impact of CVE-2016-1156 extends beyond simple application crashes to potentially affect user trust and platform reliability. When users encounter application instability or crashes during normal timeline browsing activities, it can lead to reduced adoption and increased support requests for the messaging service. The vulnerability's presence in widely deployed client applications means that successful exploitation can affect numerous users simultaneously, particularly during peak usage hours when timeline content is most actively consumed. From a security perspective, this vulnerability demonstrates the importance of proper input validation and defensive programming practices in client-side applications. The flaw aligns with ATT&CK technique T1499.004, which covers "Network Denial of Service" through application-level attacks, and represents a classic example of how seemingly benign user interface rendering operations can become attack vectors when proper security controls are absent. Organizations should consider this vulnerability as part of broader application security hygiene practices and implement comprehensive input validation mechanisms to prevent similar issues in future releases.
Mitigation strategies for CVE-2016-1156 should focus on immediate version updates and implementation of robust input validation controls. Users should upgrade to LINE versions that address this vulnerability, which typically involves patching the timeline display logic to properly handle malformed or crafted post content. Security teams should implement content filtering mechanisms that sanitize user-generated content before display operations, particularly focusing on timeline rendering components. The vulnerability highlights the importance of defensive programming practices including bounds checking, input sanitization, and proper error handling in client applications. Organizations should also consider implementing monitoring solutions that can detect unusual application crash patterns or service disruption events that might indicate exploitation attempts. Additionally, user education regarding suspicious content and account security practices can help reduce the risk of compromised accounts being used as attack vectors for this type of vulnerability.