CVE-2021-21379
MEDIUMCVE-2021-21379 is a medium-severity (CVSS 5.4) CWE-281 vulnerability in org.xwiki.platform:xwiki-platform-rendering-wikimacro-store. O3 Security confirms whether CVE-2021-21379 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
It's possible to execute anything with the rights of the author of a macro which uses the {{wikimacrocontent}} macro
Blast Radius
org.xwiki.platform:xwiki-platform-rendering-wikimacro-store☕org.xwiki.platform:xwiki-platform-rendering-wikimacro-store☕org.xwiki.platform:xwiki-platform-rendering-wikimacro-storeReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.
Description
XWiki Platform is a generic wiki platform offering runtime services for applications built on top of it. In affected versions of XWiki Platform, the {{wikimacrocontent}} executes the content with the rights of the wiki macro author instead of the caller of that wiki macro. This makes possible to inject scripts through it and they will be executed with the rights of the wiki macro (very often a user which has Programming rights). Fortunately, no such macro exists by default in XWiki Standard but one could have been created or installed with an extension. This vulnerability has been patched in versions XWiki 12.6.3, 11.10.11 and 12.8-rc-1. There is no easy workaround other than disabling the affected macros. Inserting content in a safe way or knowing what is the user who called the wiki macro is not easy.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.xwiki.platform:xwiki-platform-rendering-wikimacro-store | ≥ 11.4&&< 11.10.11 | 11.10.11 |
| ☕Maven | org.xwiki.platform:xwiki-platform-rendering-wikimacro-store | ≥ 12.0&&< 12.6.3 | 12.6.3 |
| ☕Maven | org.xwiki.platform:xwiki-platform-rendering-wikimacro-store | ≥ 12.7&&< 12.8 | 12.8 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.xwiki.platform:xwiki-platform-rendering-wikimacro-store. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update org.xwiki.platform:xwiki-platform-rendering-wikimacro-store to 11.10.11 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-21379 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2021-21379 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2021-21379. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2021-21379 in your dependencies?
O3 detects CVE-2021-21379 across Maven dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.