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Moderate severityNVD Advisory· Published Nov 3, 2021· Updated Aug 4, 2024

XSS vulnerability allowing arbitrary JavaScript execution

CVE-2021-41174

Description

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 packages

Versions sourced from the GitHub Security Advisory.

PackageAffected versionsPatched versions
@grafana/datanpm
>= 8.0.0, < 8.2.38.2.3

Affected products

1

Patches

3
fb85ed691290

Merge pull request #147 from grafana/axelav/sanitized-nav-links-8-2-3

https://github.com/grafana/grafanaOscar KilhedOct 25, 2021via ghsa
commit
1 file changed · +5 −3
  • public/app/core/components/NavBar/DropdownChild.tsx+5 −3 modified
    @@ -1,6 +1,6 @@
 import React from 'react';
 import { css } from '@emotion/css';
-import { GrafanaTheme2 } from '@grafana/data';
+import { GrafanaTheme2, textUtil } from '@grafana/data';
 import { Icon, IconName, Link, useTheme2 } from '@grafana/ui';
 
 export interface Props {
@@ -29,13 +29,15 @@ const DropdownChild = ({ isDivider = false, icon, onClick, target, text, url }:
     </button>
   );
   if (url) {
+    const sanitizedUrl = textUtil.sanitizeAngularInterpolation(url);
+
     element =
       !target && url.startsWith('/') ? (
-        <Link className={styles.element} onClick={onClick} href={url}>
+        <Link className={styles.element} onClick={onClick} href={sanitizedUrl}>
           {linkContent}
         </Link>
       ) : (
-        <a className={styles.element} href={url} target={target} rel="noopener" onClick={onClick}>
+        <a className={styles.element} href={sanitizedUrl} target={target} rel="noopener" onClick={onClick}>
           {linkContent}
         </a>
       );
3cb5214fa45e

Merge pull request #151 from grafana/dcech/sanitize-replaceAll

https://github.com/grafana/grafanaDimitris SotirakisOct 25, 2021via ghsa
commit
1 file changed · +1 −1
  • packages/grafana-data/src/text/sanitize.ts+1 −1 modified
    @@ -40,5 +40,5 @@ export function escapeHtml(str: string): string {
 }
 
 export function sanitizeAngularInterpolation(url: string): string {
-  return url.replace('{{', '%7B%7B').replace('}}', '%7D%7D');
+  return url.replace(/\{\{/g, '%7B%7B').replace(/\}\}/g, '%7D%7D');
 }
31b78d51c693

Merge pull request #146 from grafana/oscark/sanitize-nav-links

https://github.com/grafana/grafanaDimitris SotirakisOct 22, 2021via ghsa
commit
4 files changed · +12 −12
  • packages/grafana-data/src/text/index.ts+2 −1 modified
    @@ -1,11 +1,12 @@
 export * from './string';
 export * from './markdown';
 export * from './text';
-import { escapeHtml, hasAnsiCodes, sanitize, sanitizeUrl } from './sanitize';
+import { escapeHtml, hasAnsiCodes, sanitize, sanitizeUrl, sanitizeAngularInterpolation } from './sanitize';
 
 export const textUtil = {
   escapeHtml,
   hasAnsiCodes,
   sanitize,
   sanitizeUrl,
+  sanitizeAngularInterpolation,
 };
  • packages/grafana-data/src/text/sanitize.ts+4 −0 modified
    @@ -38,3 +38,7 @@ export function hasAnsiCodes(input: string): boolean {
 export function escapeHtml(str: string): string {
   return String(str).replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;').replace(/"/g, '&quot;');
 }
+
+export function sanitizeAngularInterpolation(url: string): string {
+  return url.replace('{{', '%7B%7B').replace('}}', '%7D%7D');
+}
  • public/app/angular/AngularApp.ts+0 −6 modified
    @@ -103,12 +103,6 @@ export class AngularApp {
   }
 
   bootstrap() {
-    // Do not initalize angular when the path contains an interpolation directive
-    const { pathname } = window.location;
-    if (pathname && (pathname.includes('%7B%7B') || pathname.includes('{{'))) {
-      return;
-    }
-
     const injector = angular.bootstrap(document, this.ngModuleDependencies);
 
     monkeyPatchInjectorWithPreAssignedBindings(injector);
  • public/app/core/components/NavBar/NavBarItem.tsx+6 −5 modified
    @@ -1,6 +1,6 @@
 import React, { ReactNode } from 'react';
 import { css, cx } from '@emotion/css';
-import { GrafanaTheme2, NavModelItem } from '@grafana/data';
+import { GrafanaTheme2, NavModelItem, textUtil } from '@grafana/data';
 import { Link, useTheme2 } from '@grafana/ui';
 import NavBarDropdown from './NavBarDropdown';
 
@@ -34,13 +34,14 @@ const NavBarItem = ({
       <span className={styles.icon}>{children}</span>
     </button>
   );
+  const sanitizedUrl = textUtil.sanitizeAngularInterpolation(url ?? '');
 
   if (url) {
     element =
-      !target && url.startsWith('/') ? (
+      !target && sanitizedUrl.startsWith('/') ? (
         <Link
           className={styles.element}
-          href={url}
+          href={sanitizedUrl}
           target={target}
           aria-label={label}
           onClick={onClick}
@@ -49,7 +50,7 @@ const NavBarItem = ({
           <span className={styles.icon}>{children}</span>
         </Link>
       ) : (
-        <a href={url} target={target} className={styles.element} onClick={onClick} aria-label={label}>
+        <a href={sanitizedUrl} target={target} className={styles.element} onClick={onClick} aria-label={label}>
           <span className={styles.icon}>{children}</span>
         </a>
       );
@@ -61,7 +62,7 @@ const NavBarItem = ({
       <NavBarDropdown
         headerTarget={target}
         headerText={label}
-        headerUrl={url}
+        headerUrl={sanitizedUrl}
         items={menuItems}
         onHeaderClick={onClick}
         reverseDirection={reverseMenuDirection}

Vulnerability mechanics

Generated by null/stub on May 9, 2026. Inputs: CWE entries + fix-commit diffs from this CVE's patches. Citations validated against bundle.

References

8

News mentions

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