cbcvebase.
CVE-2021-41174
published 2021-11-03

CVE-2021-41174: Grafana is an open-source platform for monitoring and observability. In affected versions if an attacker is able to convince a victim to visit a URL…

PriorityP277medium6.1CVSS 3.1
AVNACLPRNUIRSCCLILAN
ITWEXPLOITVulnCheck KEV
Exploited in the wild
EPSS
84.61%
99.7th percentile
Grafana is an open-source platform for monitoring and observability. In affected versions if an attacker is able to convince a victim to visit a URL referencing a vulnerable page, arbitrary JavaScript content may be executed within the context of the victim's browser. The user visiting the malicious link must be unauthenticated and the link must be for a page that contains the login button in the menu bar. The url has to be crafted to exploit AngularJS rendering and contain the interpolation binding for AngularJS expressions. AngularJS uses double curly braces for interpolation binding: {{ }} ex: {{constructor.constructor(‘alert(1)’)()}}. When the user follows the link and the page renders, the login button will contain the original link with a query parameter to force a redirect to the login page. The URL is not validated and the AngularJS rendering engine will execute the JavaScript expression contained in the URL. Users are advised to upgrade as soon as possible. If for some reason you cannot upgrade, you can use a reverse proxy or similar to block access to block the literal string {{ in the path.

Affected

3 ranges
VendorProductVersion rangeFixed in
grafanadata>= 8.0.0 < 8.2.38.2.3
grafanagrafana
grafanagrafana>= 8.0.0 < 8.2.38.2.3

Detection & IOCsextracted from sources · hover to see the quote

url/dashboard/snapshot/%7B%7Bconstructor.constructor(%27alert(document.domain)%27)()%7D%7D?orgId=1
yara
regex: '"subTitle":"Grafana (v8\.(?:(?:1|0)\.[0-9]|2\.[0-2]))'
  • Look for URL-encoded double curly braces (%7B%7B / %7D%7D) in HTTP request paths targeting Grafana /dashboard/snapshot/ endpoints, indicating AngularJS interpolation injection attempts.
  • Block or alert on requests containing the literal string '{{' in the URL path to Grafana, as recommended by the advisory for reverse proxy mitigations.
  • Fingerprint vulnerable Grafana instances by matching HTTP response body for both 'Grafana' and 'frontend_boot_js_done_time_seconds', combined with a subTitle version string matching v8.0.x, v8.1.x, or v8.2.0–8.2.2.
  • Use Shodan/FOFA queries to identify exposed Grafana instances: Shodan title:"Grafana", FOFA title="grafana", Google intitle:"grafana".
  • The attack targets unauthenticated pages that render the login button; monitor for XSS payloads delivered via the redirect/login flow on Grafana snapshot or dashboard pages.
  • ·Vulnerable version range is Grafana 8.0.0 through 8.2.2 only; versions outside this range (including older versions shipped with RHEL 8/9 and OpenShift 4) are not affected.
  • ·The exploit requires the victim to be unauthenticated; authenticated sessions are not directly targeted by this vector.

CVSS provenance

nvdv3.16.1MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
nvdv2.04.3MEDIUMAV:N/AC:M/Au:N/C:N/I:P/A:N
ghsa6.1MEDIUM
osv6.1MEDIUM
vulncheck6.9MEDIUM
vendor_redhat6.9MEDIUM
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