#VU57320 Improper access control in Grafana - CVE-2021-39226

Vulnerability identifier: #VU57320

Vulnerability risk: Medium

CVSSv4.0: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:A/U:Green]

CVE-ID: CVE-2021-39226

CWE-ID: CWE-284

Exploitation vector: Network

Exploit availability: Yes

Vulnerable software:
Grafana
Web applications / Other software

Vendor: Grafana Labs

Description

The vulnerability allows a remote attacker to gain unauthorized access to otherwise restricted functionality.

The vulnerability exists due to improper access restrictions to database snapshots. Remote unauthenticated and authenticated users are able to view the snapshot with the lowest database key by accessing the literal paths: /dashboard/snapshot/:key, or /api/snapshots/:key. If the snapshot "public_mode" configuration setting is set to true (vs default of false), unauthenticated users are able to delete the snapshot with the lowest database key by accessing the literal path: /api/snapshots-delete/:deleteKey.

Regardless of the snapshot "public_mode" setting, authenticated users are able to delete the snapshot with the lowest database key by accessing the literal paths: /api/snapshots/:key, or /api/snapshots-delete/:deleteKey. The combination of deletion and viewing enables a complete walk through all snapshot data while resulting in complete snapshot data loss.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Grafana: 7.5.0 - 7.5.10, 8.1.0 - 8.1.5

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External links
https://github.com/grafana/grafana/commit/2d456a6375855364d098ede379438bf7f0667269
https://grafana.com/docs/grafana/latest/release-notes/release-notes-8-1-6/
https://github.com/grafana/grafana/security/advisories/GHSA-69j6-29vr-p3j9
https://grafana.com/docs/grafana/latest/release-notes/release-notes-7-5-11/
https://www.openwall.com/lists/oss-security/2021/10/05/4

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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?

Yes. This vulnerability is being exploited in the wild.