Authentication bypass in Grafana Azure AD OAuth

1) Improper Authentication

EUVDB-ID: #VU77652

Risk: High

CVSSv3.1: 7.9 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2023-3128

CWE-ID: CWE-287 - Improper Authentication

Exploit availability: No

Description

The vulnerability allows a remote attacker to bypass authentication process.

The vulnerability exists due to an error in Azure AD OAuth implementation. Grafana is validating Azure AD accounts based on the email claim. On Azure AD, the profile email field is not unique and can be easily modified. A remote attacker can modify their profile and provide the email address of  an existing Grafana user, bypass authentication process and gain unauthorized access to the application.

The vulnerability affects Grafana installations with Azure AD OAuth configured for a multi-tenant app.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Grafana: 9.2.0 - 9.3.15

External links

http://github.com/grafana/grafana/releases/tag/v9.3.16
http://github.com/grafana/grafana/releases/tag/v9.2.20
http://grafana.com/security/security-advisories/cve-2023-3128/

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.