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.
This vulnerability carries a CRITICAL severity rating with a CVSS v3.1 score of 9.0, indicating it can be exploited remotely over the network with relatively low complexity though user interaction is required requiring only low-level privileges . The vulnerability impacts confidentiality (data exposure), integrity (unauthorized modifications), and availability (service disruption) for affected systems. Impacting 1 product from openwebui organizations running these solutions should prioritize assessment and patching.
Reported in 2025, this vulnerability emerged during an era marked by increased sophistication in supply chain attacks, cloud infrastructure vulnerabilities, and software-as-a-service (SaaS) security challenges. Security practices during this period emphasized zero-trust architectures, container security, and API protection.
2025-03-20T10:15:36.217
2025-04-01T20:33:49.153
Analyzed
CVSSv3.1: 9.0 (CRITICAL)
| Type | Vendor | Product | Version/Range | Vulnerable? |
|---|---|---|---|---|
| Application | openwebui | open_webui | 0.3.8 | Yes |
SecUtils normalizes and enriches National Vulnerability Database (NVD) records by standardizing vendor and product identifiers, aggregating vulnerability metadata from both NVD and MITRE sources, and providing structured context for security teams. For openwebui's affected products, we extract Common Platform Enumeration (CPE) data, Common Weakness Enumeration (CWE) classifications, CVSS severity metrics, and reference data to enable rapid vulnerability prioritization and asset correlation. This record contains no exploit code, proof-of-concept instructions, or attack methodologies—only defensive intelligence necessary for patch management, risk assessment, and security operations.