Overview
CVE-2025-41076 describes an information disclosure vulnerability found in LimeSurvey version 6.13.0. This flaw allows an unauthenticated, external attacker to trigger a 500 error by sending a specially crafted, malformed session cookie to the application. Critically, instead of displaying a generic error, the system inadvertently exposes sensitive internal backend information. This exposed information can aid attackers in further reconnaissance and potential exploitation.
Technical Details
The vulnerability stems from inadequate error handling when processing session cookies. When a malformed cookie is received, LimeSurvey attempts to process it but fails. The resulting exception is not properly masked, leading to a detailed error message being displayed. This error message reveals:
- The use of the Yii framework.
- The database engine in use: MySQL/MariaDB.
- The name of the session table: ‘lime_sessions’.
- Primary key information.
- Fragments of the content causing the conflict within the cookie data itself.
This leaked information provides a significant advantage to attackers as it drastically reduces the effort required to map out the application’s architecture and identify potential attack vectors.
CVSS Analysis
Currently, a CVSS score is not available (N/A) for CVE-2025-41076. However, while it may not directly lead to remote code execution, the information disclosure aspect is significant. A future CVSS score will likely reflect the severity of the disclosed data, affecting confidentiality, but with a low impact on availability or integrity.
Possible Impact
The information disclosed through this vulnerability can significantly aid attackers in:
- Mapping the application’s architecture: Understanding the framework and database used allows attackers to focus their efforts on specific vulnerabilities relevant to those technologies.
- Identifying potential attack vectors: Knowing the database table names and primary keys can be leveraged in SQL injection or other database-related attacks.
- Accelerating reconnaissance: The exposed information reduces the time and effort required to gather intelligence about the target system.
While the vulnerability doesn’t immediately grant code execution, it significantly lowers the barrier to entry for more sophisticated attacks.
Mitigation or Patch Steps
The primary mitigation step is to upgrade LimeSurvey to a version that addresses this vulnerability. Check the LimeSurvey website for the latest security patches and upgrade instructions. Until a patch is applied, consider implementing the following workarounds:
- Implement robust error handling: Ensure that application errors are properly masked and do not expose sensitive internal information. Customize error pages to display generic messages instead of detailed stack traces.
- Web Application Firewall (WAF) rules: Configure a WAF to filter out malformed session cookies and block requests that trigger the 500 error. This should be considered a temporary measure, not a replacement for patching.
IMPORTANT: Applying the official patch released by LimeSurvey is the recommended and most effective solution.
