CVE-2020-27304: civetweb_project civetweb Relative Path Traversal

Vulnerability summary

CVE-2020-27304 is a critical (CVSS 9.8) Relative Path Traversal vulnerability in civetweb_project civetweb. EPSS estimates a 3.24% chance of exploitation in the next 30 days, higher than 88.1% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 21-10-2021
   PublishedVulnerability first disclosed.
2. 04-08-2024
   Last modifiedVulnerability information updated.

Description

The CivetWeb web library does not validate uploaded filepaths when running on an OS other than Windows, when using the built-in HTTP form-based file upload mechanism, via the mg_handle_form_request API. Web applications that use the file upload form handler, and use parts of the user-controlled filename in the output path, are susceptible to directory traversal

• CWE-23Relative Path TraversalThe product uses external input to construct a pathname that should be within a restricted directory, but it does not properly neutralize sequences such as ".." that can resolve to a location that is outside of that directory.
• CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.