CVE-2023-48132 in mini-app on Line
Summary
by MITRE • 01/26/2024
An issue in kosei entertainment esportsstudioLegends mini-app on Line v13.6.1 allows attackers to send crafted malicious notifications via leakage of the channel access token.
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Analysis
by VulDB Data Team • 06/21/2025
The vulnerability identified as CVE-2023-48132 represents a critical security flaw within the kosei entertainment esportsstudioLegends mini-app running on the Line messaging platform version 13.6.1. This issue stems from improper handling of channel access tokens, which are essential credentials used by Line's messaging infrastructure to authenticate and authorize communication between applications and the platform's servers. The flaw allows malicious actors to exploit a token leakage mechanism that exposes sensitive authentication credentials to unauthorized parties.
The technical implementation of this vulnerability involves a weakness in the mini-app's notification delivery system where channel access tokens are inadvertently exposed during the transmission of malicious notifications. These tokens function as bearer credentials that grant full access to specific messaging channels and can be used by attackers to send notifications to any user within the targeted channel. The flaw typically occurs when the application fails to properly validate or sanitize input parameters before processing notification requests, creating a path for attackers to inject crafted payloads that trigger the leakage of these critical tokens.
From an operational perspective, this vulnerability presents significant risks to both the platform's users and the organization operating the mini-app. Attackers can leverage the leaked channel access tokens to send spam notifications, phishing messages, or malicious payloads to unsuspecting users within the affected channels. The impact extends beyond simple notification abuse as these tokens can potentially be used to access additional platform features, read user communications, or even impersonate legitimate applications. The vulnerability particularly affects the mini-app's user base who may receive notifications from compromised channels, creating a vector for social engineering attacks and potential data exfiltration.
The security implications of CVE-2023-48132 align with CWE-200, which addresses information exposure, and represents a classic example of credential leakage through improper input handling. This vulnerability can be mapped to ATT&CK technique T1566, specifically the "Phishing for Information" sub-technique, where attackers use compromised credentials to establish persistent access to communication channels. The flaw also demonstrates characteristics of credential stuffing and token reuse attacks, where stolen authentication tokens are leveraged to gain unauthorized access to platform resources. Organizations should consider implementing token rotation mechanisms and proper input validation as core mitigation strategies to prevent exploitation of similar vulnerabilities.
Mitigation efforts should focus on immediate patching of the affected Line platform version and implementation of proper token management practices within the mini-app. The application should enforce strict validation of all notification parameters and implement secure token handling procedures that prevent unauthorized access to channel credentials. Additionally, organizations should deploy monitoring systems to detect unusual notification patterns and establish automated token revocation processes that can quickly invalidate compromised credentials. The fix should include proper error handling that prevents sensitive information leakage and ensures that authentication tokens are never exposed during normal operation. Regular security audits and penetration testing should be conducted to identify similar vulnerabilities in the platform's ecosystem and ensure comprehensive protection against credential-based attacks.