Affected versions of tinyserver2 resolve relative file paths, resulting in a directory traversal vulnerability. A malicious actor can use this vulnerability to access files outside of the intended directory root, which may result in the disclosure of private files on the vulnerable system.

Example request:

GET /../../../../../../../../../../etc/passwd HTTP/1.1
host:foo

Recommendation

Update to v0.6.0 or later.

References

• https://nvd.nist.gov/vuln/detail/CVE-2017-16085
• https://github.com/JacksonGL/NPM-Vuln-PoC/tree/master/directory-traversal/tinyserver2
• GHSA-g8wf-rcg3-qw4q
• https://www.npmjs.com/advisories/371