Security advisory for YesWiki

Advisory overview

YesWiki before 4.7.0 contains a server-side request forgery vulnerability in the Bazar CSV import copyUrlToLocalFile() function that allows authenticated administrators to make arbitrary outbound requests by supplying crafted URLs in CSV file or image fields. Attackers can bypass the extension check with a query-string suffix or redirects to fetch cloud metadata credentials, internal services, or local files via file://, with responses stored in the web-accessible files/ directory.

Related references

• https://github.com/YesWiki/yeswiki/security/advisories/GHSA-v38g-qc7g-q3mq
• https://www.vulncheck.com/advisories/yeswiki-before-4.7.0-ssrf-via-copyurltolocalfile-in-bazar-csv-import