Brute force takeover of OpenID Connect session cookies in sftpgo

Vulnerability Description

sftpgo is a full-featured and highly configurable event-driven file transfer solution. Server protocols: SFTP, HTTP/S, FTP/S, WebDAV. The OpenID Connect implementation allows authenticated users to brute force session cookies and thereby gain access to other users' data, since the cookies are generated predictably using the xid library and are therefore unique but not cryptographically secure. This issue was fixed in version v2.6.4, where cookies are opaque and cryptographically secure strings. All users are advised to upgrade. There are no known workarounds for this vulnerability.

References

• https://github.com/drakkan/sftpgo/security/advisories/GHSA-6943-qr24-82vx
• https://github.com/drakkan/sftpgo/commit/f30a9a2095bf90c0661b04fe038e3b7efc788bc6
• https://github.com/rs/xid