Open WebUI Vulnerable to a Session Fixation Attack
Date: 2025-03
Affected: pip/open-webui
Attack vector: rce
Category: vulnerability-disclosure
Severity: High
CVE: CVE-2024-7053
CWE: CWE-79
CVSS: 7.6 (CVSS:3.0/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:L/A:N)

A vulnerability in open-webui/open-webui version 0.3.8 allows an attacker with a user-level account to perform a session fixation attack. The session cookie for all users is set with the default `SameSite=Lax` and does not have the `Secure` flag enabled, allowing the session cookie to be sent over HTTP to a cross-origin domain. An attacker can exploit this by embedding a malicious markdown image in a chat, which, when viewed by an administrator, sends the admin's session cookie to the attacker's server. This can lead to a stealthy administrator account takeover, potentially resulting in remote code execution (RCE) due to the elevated privileges of administrator accounts.


Mitigations:

Architectural layers (MAESTRO):