CVE-2023-39733 in Line
Summary
by MITRE • 10/25/2023
The leakage of the client secret in TonTon-Tei Line v13.6.1 allows attackers to obtain the channel access token and send crafted broadcast messages.
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Analysis
by VulDB Data Team • 01/26/2026
The vulnerability identified as CVE-2023-39733 represents a critical security flaw in the TonTon-Tei Line mobile application version 13.6.1 which exposes client secret credentials through improper handling of authentication tokens. This flaw falls under the category of credential exposure and directly violates security best practices for mobile application development. The vulnerability stems from the application's failure to properly secure sensitive authentication parameters during the token acquisition process, creating an opportunity for malicious actors to intercept and exploit these credentials.
The technical implementation of this vulnerability involves the insecure storage and transmission of client secrets within the application's codebase or configuration files. When the mobile application attempts to obtain channel access tokens for broadcasting messages, it inadvertently exposes the client secret through network traffic interception or code analysis. This represents a fundamental failure in the application's security architecture and demonstrates poor adherence to secure coding practices. The vulnerability is particularly concerning as it enables unauthorized parties to gain elevated privileges within the messaging platform's ecosystem.
From an operational standpoint, this vulnerability creates significant risks for organizations using the TonTon-Tei Line platform for business communications. Attackers who exploit this flaw can craft and send unauthorized broadcast messages to all channel members, potentially leading to spam campaigns, misinformation dissemination, or even social engineering attacks. The impact extends beyond simple message broadcasting as the compromised credentials could enable further exploitation attempts against the underlying messaging infrastructure. This vulnerability directly maps to attack patterns described in the MITRE ATT&CK framework under credential access and command and control phases, where adversaries seek to establish persistent access and control over communication channels.
The security implications of this vulnerability are compounded by the potential for lateral movement within the affected organization's communication ecosystem. Once attackers obtain the client secret, they can potentially access additional services or resources that share the same authentication mechanism, creating a pathway for more extensive compromise. Organizations should consider this vulnerability as part of a broader attack surface that includes potential data exfiltration, reputation damage, and compliance violations. The exposure of client secrets also violates common security standards such as those outlined in the CWE catalog under CWE-312 and CWE-522, which address the exposure of sensitive information and insufficiently protected credentials.
Mitigation strategies should include immediate application updates to properly secure client secrets, implementation of secure credential storage mechanisms, and network monitoring to detect unauthorized access attempts. Organizations should also conduct comprehensive security assessments of their mobile applications and implement proper code review processes to prevent similar vulnerabilities. The remediation process should involve thorough credential rotation, enhanced network security controls, and regular security testing to ensure that authentication mechanisms remain robust against evolving attack vectors. Additionally, security teams should establish monitoring procedures to detect anomalous message broadcasting activities that could indicate exploitation of this vulnerability.