Description
Rallly is an open-source scheduling and collaboration tool. Versions up to and including 3.22.1 of the application features token based authentication. When a user attempts to login to the application, they insert their email and a 6 digit code is sent to their email address to complete the authentication. A token that consists of 6 digits only presents weak entropy however and when coupled with no token brute force protection, makes it possible for an unauthenticated attacker with knowledge of a valid email address to successfully brute force the token within 15 minutes (token expiration time) and take over the account associated with the targeted email address. All users on the Rallly applications are impacted. As long as an attacker knows the user's email address they used to register on the app, they can systematically take over any user account. For the authentication mechanism to be safe, the token would need to be assigned a complex high entropy value that cannot be bruteforced within reasonable time, and ideally rate limiting the /api/auth/callback/email endpoint to further make brute force attempts unreasonable within the 15 minutes time. As of time of publication, no patched versions are available.
EPSS Score:
0%
Comprehensive Technical Analysis of EUVD-2025-14949
1. Vulnerability Assessment and Severity Evaluation
Vulnerability Description: The vulnerability in Rallly, an open-source scheduling and collaboration tool, involves a weak token-based authentication mechanism. Specifically, the token used for authentication consists of only 6 digits, which provides weak entropy. This, combined with the lack of brute force protection, allows an unauthenticated attacker to brute force the token within the 15-minute expiration window, thereby taking over any user account.
Severity Evaluation:
The CVSS (Common Vulnerability Scoring System) base score of 9.8 indicates a critical vulnerability. The scoring vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H breaks down as follows:
- Attack Vector (AV): Network (N) - The vulnerability is exploitable over the network.
- Attack Complexity (AC): Low (L) - The attack requires minimal skill or resources.
- Privileges Required (PR): None (N) - No privileges are required to exploit the vulnerability.
- User Interaction (UI): None (N) - No user interaction is required.
- Scope (S): Unchanged (U) - The vulnerability does not change the security scope.
- Confidentiality (C): High (H) - Complete loss of confidentiality.
- Integrity (I): High (H) - Complete loss of integrity.
- Availability (A): High (H) - Complete loss of availability.
2. Potential Attack Vectors and Exploitation Methods
Attack Vectors:
- Brute Force Attack: An attacker can systematically attempt all possible 6-digit combinations (10^6 = 1,000,000 combinations) within the 15-minute window to gain unauthorized access.
- Email Enumeration: If an attacker can enumerate valid email addresses, they can target specific accounts for takeover.
Exploitation Methods:
- Automated Scripts: Attackers can use automated scripts to rapidly test all possible 6-digit combinations.
- Rate Limiting Bypass: If rate limiting is not implemented or can be bypassed, the attack becomes more feasible.
3. Affected Systems and Software Versions
Affected Systems:
- All users of the Rallly application.
Software Versions:
- Versions up to and including 3.22.1.
4. Recommended Mitigation Strategies
Immediate Mitigations:
- Rate Limiting: Implement rate limiting on the
/api/auth/callback/emailendpoint to restrict the number of authentication attempts within the 15-minute window. - Complex Tokens: Increase the complexity and entropy of the authentication tokens to make brute force attacks infeasible.
- Monitoring and Alerts: Implement monitoring to detect and alert on suspicious login attempts.
Long-Term Mitigations:
- Multi-Factor Authentication (MFA): Introduce MFA to add an additional layer of security.
- Regular Security Audits: Conduct regular security audits and penetration testing to identify and mitigate similar vulnerabilities.
5. Impact on European Cybersecurity Landscape
Impact Analysis:
- User Trust: Compromised user accounts can lead to a loss of trust in the application and the broader ecosystem.
- Data Breaches: Unauthorized access can result in data breaches, leading to potential legal and financial repercussions under GDPR.
- Reputation: The vulnerability can negatively impact the reputation of the application and its developers.
Regulatory Compliance:
- GDPR Compliance: Organizations using Rallly must ensure they comply with GDPR regulations, particularly in terms of data protection and breach notification.
6. Technical Details for Security Professionals
Technical Analysis:
- Token Entropy: A 6-digit token provides 1,000,000 possible combinations, which is insufficient for secure authentication.
- Brute Force Feasibility: With no rate limiting, an attacker can attempt all combinations within the 15-minute window, making the attack highly feasible.
- Endpoint Vulnerability: The
/api/auth/callback/emailendpoint is the primary target for brute force attacks.
Mitigation Implementation:
- Rate Limiting: Implement a rate limit of 5 attempts per minute to significantly reduce the feasibility of brute force attacks.
- Token Complexity: Increase token length to at least 8 characters, including alphanumeric and special characters, to enhance entropy.
- Logging and Monitoring: Enable detailed logging of authentication attempts and set up alerts for multiple failed attempts from the same IP address.
Conclusion: The vulnerability in Rallly highlights the importance of robust authentication mechanisms and the need for continuous security assessments. Immediate mitigations should focus on rate limiting and increasing token complexity, while long-term strategies should include MFA and regular security audits. The impact on the European cybersecurity landscape underscores the need for compliance with GDPR and maintaining user trust.
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