Permissive Regular Expression Enables Console Authentication Bypass

Tegalog, a memo logging application by Nishishi Factory, contains a critical authentication vulnerability stemming from overly permissive regular expression validation. The flaw allows attackers with access to the affected product to bypass authentication controls and gain unauthorized access to the management console. Once authenticated, an attacker gains full operational privileges, enabling them to modify logs, manipulate system configurations, and potentially destroy audit trails—making this particularly dangerous for organizations relying on Tegalog for security monitoring and compliance logging. Any organization deploying Tegalog in their infrastructure faces immediate risk of console compromise and loss of logging integrity.

While this CVE does not map to specific MITRE ATT&CK techniques, Casky's security skills would identify attack patterns associated with credential bypass and unauthorized system access. Practitioners using Casky would detect anomalies in authentication workflows, including malformed input that exploits regex weaknesses, unusual console access patterns, and privilege escalation attempts. Claude's extended reasoning capabilities would correlate these indicators across logs to surface suspicious authentication sequences—such as repeated failed login attempts followed by sudden success, or console access from unexpected sources. Security teams would see findings highlighting the regex validation failure as an entry point for T1078 (Valid Accounts) style attacks, enabling faster detection and response to potential console compromises before attackers can manipulate critical audit data.