CVE-2026-63237 in Koollab LMS
Summary
by MITRE • 07/29/2026
A TOTP two-factor authentication bypass vulnerability in Koollab LMS allowed an attacker to supply a client-controlled seed to generate a matching one-time password and bypass the second authentication factor, potentially enabling unauthorised access to administrator accounts.
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Analysis
by VulDB Data Team • 07/29/2026
This vulnerability represents a critical weakness in the time-based one-time password implementation within Koollab Learning Management System that fundamentally undermines the security of its two-factor authentication mechanism. The flaw occurs when the system accepts a client-controlled seed value during the TOTP generation process, allowing an attacker to manipulate the cryptographic parameters used to create valid one-time passwords. This bypasses the intended security controls by enabling unauthorized parties to generate authentic-looking tokens without possessing the legitimate secret key or physical token required for proper authentication.
The technical nature of this vulnerability aligns with CWE-310, which addresses cryptographic weaknesses and improper use of cryptographic primitives. Specifically, this issue demonstrates poor implementation of the TOTP algorithm where the system fails to enforce proper entropy requirements and validation of seed values. The attacker can supply any arbitrary seed value that produces a matching one-time password, effectively nullifying the second factor authentication requirement. This represents a direct violation of security principle 10 from the NIST Cybersecurity Framework, which emphasizes the importance of implementing robust authentication mechanisms.
The operational impact of this vulnerability is severe as it provides attackers with a pathway to compromise administrator accounts within the learning management system. Successful exploitation allows unauthorized access to sensitive educational data, user information, and administrative functions that control course content, user permissions, and system configurations. The attack vector typically involves intercepting or manipulating authentication requests where the system accepts user-supplied seed values instead of using properly generated cryptographic seeds. This vulnerability also maps to ATT&CK technique T1566 which covers credential harvesting through social engineering and technical means.
Mitigation strategies should focus on implementing strict validation of seed generation parameters within the TOTP implementation, ensuring that only cryptographically secure random values are accepted for authentication purposes. System administrators must enforce proper input sanitization and cryptographic key management practices to prevent client-controlled inputs from influencing the TOTP calculation process. Additional measures include implementing rate limiting on authentication attempts, monitoring for unusual authentication patterns, and conducting regular security assessments of authentication mechanisms. The organization should also consider implementing multi-factor authentication solutions that do not rely on potentially vulnerable cryptographic implementations, while ensuring all authentication components follow established standards such as RFC 6238 for TOTP implementation and NIST SP 800-63B for digital identity management practices.