Laurentius Von Oppenkowski

**Name of the Vulnerable Software and Affected Versions** syracom AG Secure Login (2FA) for Atlassian Jira, Confluence, and Bitbucket versions 3.4.0.x **Description** An authentication bypass exists where an attacker with valid user credentials can circumvent the two-factor authentication (2FA) flow. By sending HTTP requests with a crafted `User-Agent` header containing specific strings such as AtlassianMobileApp or JIRA, the plugin fails to enforce 2FA checks for protected web resources. This allows unauthorized access to the Atlassian application as the compromised user. If the account possesses administrative privileges, the attacker can access administrative functions, potentially disabling the 2FA plugin or making arbitrary changes. **Recommendations** Update to version 3.5.0.0.