جزئیات آسیب‌پذیری

YesWiki is a wiki system written in PHP. From version 4.6.2 to before version 4.6.6, the POST /api/forms/{formId}/actor/inbox route - exposed publicly with acl:"public" - accepts an HTTP Signature header whose keyId parameter is a URL. HttpSignatureService::verifySignature() parses the header and immediately makes a server-side HTTP GET to that URL, before any cryptographic verification or URL validation. An unauthenticated remote attacker can therefore make YesWiki issue arbitrary outbound HTTP requests to any host the server can reach - internal services, cloud-metadata endpoints (169.254.169.254), intranet-only admin panels, etc. - and read enough back via timing and error-message oracles to scan ports, enumerate services, and (on a real cloud instance) reach IAM metadata. The only deployment-side precondition is that ActivityPub be enabled on at least one Bazar form. This issue has been patched in version 4.6.6.

• https://github.com/YesWiki/yeswiki/releases/tag/v4.6.6 x_refsource_MISC
• http://github.com/YesWiki/yeswiki/commit/87e627f33e79879827a3669fee2aa1244612c487 x_refsource_MISC
• https://github.com/YesWiki/yeswiki/security/advisories/GHSA-vw42-752g-5mrp x_refsource_CONFIRM