GHSA-69j6-29vr-p3j9 Authentication bypass for viewing and deletions of snapshots
Today we are releasing Grafana 7.5.11, and 8.1.6. These patch releases include an important security fix for an issue that affects all Grafana versions from 2.0.1.[Grafana Cloud](https://grafana.com/cloud) instances have already been patched and an audit did not find any usage of this attack vector. [Grafana Enterprise](https://grafana.com/products/enterprise) customers were provided with updated binaries under embargo.8.1.5 contained a single fix for bar chart panels. We believe that users can expedite deployment by moving from 8.1.4 to 8.1.6 directly.CVE-2021-39226 Snapshot authentication bypassSummaryCVSS Score: 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HWe received a security report to [security@grafana.com](mailto:security@grafana.com) on 2021-09-15 about a vulnerability in Grafana regarding the snapshot feature. It was later identified as affecting Grafana versions from 2.0.1 to 8.1.6. [CVE-2021-39226](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-39226) has been assigned to this vulnerability.ImpactUnauthenticated 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.Attack auditWhile we can not guarantee that the below will identify all attacks, if you do find something with the below, you should consider doing a full assessment.Through reverse proxy/load balancer logsTo determine if your Grafana installation has been exploited for this vulnerability, search through your reverse proxy/load balancer access logs for instances where the path is `/dashboard/snapshot/:key`, `/api/snapshots/:key` or `/api/snapshots-delete/:deleteKey`, and the response status code was 200 (OK).
For example, if you’re using the Kubernetes ingress-nginx controller and sending logs to Loki, use a LogQL query like `{job="nginx-ingress-controller"} |= "\"status\": 200" |= "\"uri\": \"/api/snapshots/:key\""`.Through the Grafana Enterprise audit featureIf you enabled “Log web requests” in your configuration with `router_logging = true`, look for
`"requestUri":"/api/snapshots-delete/”`,`“requestUri":"/api/snapshots/:key"`, or `"type":"snapshot"` in combination with `"action":"delete"`.Patched versionsRelease 8.1.6:[Download Grafana 8.1.6](https://grafana.com/grafana/download/8.1.6)[Release notes](https://grafana.com/docs/grafana/latest/release-notes/release-notes-8-1-6/)Release 7.5.11:[Download Grafana 7.5.11](https://grafana.com/grafana/download/7.5.11)[Release notes](https://grafana.com/docs/grafana/latest/release-notes/release-notes-7-5-11/)Solutions and mitigationsDownload and install the appropriate patch for your version of Grafana.[Grafana Cloud](https://grafana.com/cloud) instances have already been patched, and [Grafana Enterprise](https://grafana.com/products/enterprise) customers were provided with updated binaries under embargo.WorkaroundIf for some reason you cannot upgrade:You can use a reverse proxy or similar to block access to the literal paths`/api/snapshots/:key``/api/snapshots-delete/:deleteKey``/dashboard/snapshot/:key``/api/snapshots/:key`They have no normal function and can be disabled without side effects.Timeline and postmortemHere is a detailed timeline starting from when we originally learned of the issue. All times in UTC.2021-09-15 14:49: Tuan Tran theblackturtle0901@gmail.com sends initial report about viewing snapshots without authentication2021-09-15 15:56: Initial reproduction2021-09-15 17:10: MEDIUM severity declared2021-09-15 18:58: Workaround deployed on Grafana Cloud2021-09-15 19:15: `/api/snapshots/:key` found to be vulnerable as well2021-09-15 19:30: `/api/snapshots/:key` blocked on Grafana Cloud2021-09-16 09:31: `/api/snapshots-delete/:deleteKey` found to be vulnerable as well, blocked on Grafana Cloud. From this point forward, Cloud is not affected any more.2021-09-16 09:35: HIGH severity declared2021-09-16 11:19: Realization that combination of deletion and viewing allows enumeration and permanent DoS2021-09-16 11:19: CRITICAL declared2021-09-17 10:53: Determination that no weekend work is needed. While issue is CRITICAL, scope is very limited2021-09-17 14:26: Audit of Grafana Cloud concluded, no evidence of exploitation2021-09-23: Grafana Cloud instances updated2021-09-28 12:00: Grafana Enterprise images released to customers under embargo2021-10-05 17:00: Public releaseReporting security issuesIf you think you have found a security vulnerability, please send a report to [security@grafana.com](mailto:security@grafana.com). This address can be used for all of
Grafana Labs's open source and commercial products (including but not limited to Grafana, Tempo, Loki, Amixr, k6, Tanka, and  Grafana Cloud, Grafana Enterprise, and grafana.com). We only accept vulnerability reports at this address. We would prefer that you encrypt your message to us using our PGP key. The key fingerprint is:F988 7BEA 027A 049F AE8E  5CAA D125 8932 BE24 C5CAThe key is available from [keys.gnupg.net](http://keys.gnupg.net/pks/lookup?op=get&fingerprint=on&search=0xD1258932BE24C5CA) by searching for [security@grafana](http://keys.gnupg.net/pks/lookup?search=security@grafana&fingerprint=on&op=index.Security announcementsWe maintain a category on the community site named [Security Announcements](https://community.grafana.com/c/security-announcements),
where we will post a summary, remediation, and mitigation details for any patch containing security fixes. You can also subscribe to email updates to this category if you have a grafana.com account and sign in to the community site, or via updates from our [Security Announcements RSS feed](https://community.grafana.com/c/security-announcements.rss).AcknowledgementWe would like to thank [Tran Viet Tuan](https://github.com/theblackturtle) for responsibly disclosing the initially discovered vulnerability to us.
CVSS v3.1 score: 7.3