CVE intelligence and bounded remediation

CVE-2021-29459 — XWiki Platform is a generic wiki platform offering runtime services for applications built on top of it

Critical CVSS 9.6

XWiki Platform is a generic wiki platform offering runtime services for applications built on top of it. It is possible to persistently inject scripts in XWiki versions prior to 12.6.3 and 12.8. Unregistred users can fill simple text fields. Registered users can fill in their personal information and (if they have edit rights) fill the values of static lists using App Within Minutes. There is no easy workaround except upgrading XWiki. The vulnerability has been patched on XWiki 12.8 and 12.6.3.

Severity
Critical
CVSS
9.6 (3.1)
Published
2021-04-20
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-79

Affected products

  • xwiki / xwiki

Showing 1 representative product identities from 2 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Cross-site scripting and unsafe browser output

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Check exposure

  • Trace reflected, stored, and DOM-derived untrusted values into HTML, attributes, URLs, styles, scripts, and client-side template sinks.
  • Identify affected origins, authenticated user roles, sensitive browser capabilities, and where content is shared across tenants.
  • Review framework escaping, rich-text sanitization, legacy templates, and client-side rendering paths.

Remediate safely

  • Use context-aware framework output encoding and safe DOM APIs; keep untrusted data out of executable contexts.
  • Sanitize intentionally supported markup with a maintained allowlist policy and validate URLs and attributes separately.
  • Update affected rendering components and add tests for every output context using inert sentinel markup.

Authoritative sources

Complete CVE record and remediation plan

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