Auth bypass in Limesurvey Gmbh
CVE-2025-34120
An unauthenticated file download vulnerability exists in LimeSurvey versions from 2.0+ up to and including 2.06+ Build 151014. The application fails to validate serialized input to the admin backup endpoint (`index.php/admin/update/sa/backup`), allowing attackers to specify arbitrary file paths using a crafted `datasupdateinfo` payload. The files are packaged in a ZIP archive and made available for download without authentication. This vulnerability can be exploited to read arbitrary files on the host system, including sensitive OS and configuration files.
Vulnerability class: Path Traversal (Directory Traversal)
EPSS: 0.012 (65.9th percentile) — read the EPSS interpretation.
Affected products
- Limesurvey Gmbh — versions 2.0+
Weakness classification (CWE)
Public proof-of-concept exploits
References
- disclosure@vulncheck.com (vendor-advisory, patch)
- disclosure@vulncheck.com (technical-description, third-party-advisory)
- disclosure@vulncheck.com (exploit)
- disclosure@vulncheck.com (exploit)
- disclosure@vulncheck.com (third-party-advisory)
Frequently asked questions
- What is CVE-2025-34120?
- CVE-2025-34120 is a vulnerability in Limesurvey Gmbh, classified under Path Traversal. Published 2025-07-16.
- Is CVE-2025-34120 known to be exploited?
- 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.