Overview
CVE-2025-63807 identifies a significant vulnerability in the weijiang1994 university-bbs application, also known as Blogin. Specifically, a flaw exists in the verification code generation and handling mechanism that can lead to account takeover. This vulnerability stems from a weak verification code generation process coupled with a lack of rate limiting, making the system susceptible to brute-force attacks.
Technical Details
The vulnerability resides within commit 9e06bab430bfc729f27b4284ba7570db3b11ce84 (dated 2025-01-13) of the Blogin source code. The core issue is a combination of two factors:
- Weak Verification Code Generation: The algorithm used to generate verification codes for password resets and other authentication procedures is insufficiently random or utilizes a small keyspace, making it predictable.
- Missing Rate Limiting: The application does not implement proper rate limiting on verification code attempts. This allows attackers to repeatedly submit different verification codes without encountering any restrictions, paving the way for a brute-force attack.
An attacker can exploit this by repeatedly requesting password reset tokens and then attempting a large number of possible verification codes within a short timeframe. Given the weakness of the verification code and the absence of rate limiting, the attacker has a high probability of successfully guessing the correct code.
CVSS Analysis
Currently, the severity and CVSS score for CVE-2025-63807 are listed as N/A. However, given the potential for full account takeover, this vulnerability is likely to be rated as Critical. A CVSS score will likely be assigned in the range of 9.0-10.0 upon further analysis, especially considering the potential for widespread compromise within the university-bbs system.
Possible Impact
Successful exploitation of CVE-2025-63807 can have severe consequences:
- Account Takeover: Attackers can gain complete control of user accounts, including administrator accounts.
- Data Breach: Compromised accounts can be used to access and exfiltrate sensitive user data stored within the Blogin system.
- System Compromise: If administrator accounts are compromised, attackers may be able to gain control of the entire Blogin system and potentially other connected systems.
- Reputational Damage: A successful attack can severely damage the reputation of the university and the developers of the Blogin software.
Mitigation or Patch Steps
To mitigate the risk posed by CVE-2025-63807, the following steps should be taken immediately:
- Apply the Patch (if available): Check the weijiang1994/Blogin repository or official Blogin website for a patch that addresses this vulnerability. Apply the patch as soon as possible.
- Implement Stronger Verification Code Generation: If a patch is not immediately available, replace the existing verification code generation algorithm with a cryptographically secure random number generator (CSRNG) that produces codes with sufficient entropy (at least 64 bits).
- Implement Rate Limiting: Implement rate limiting on verification code attempts to prevent brute-force attacks. A reasonable limit might be 5-10 attempts per minute per user account.
- Implement Account Lockout: After a certain number of failed verification attempts (e.g., 10), lock the account for a defined period (e.g., 30 minutes).
- Monitor for Suspicious Activity: Monitor server logs for unusual activity, such as a large number of password reset requests or failed verification attempts originating from the same IP address.
