CVE intelligence and bounded remediation

CVE-2023-34088 — Collabora Online is a collaborative online office suite

High CVSS 8.7

Collabora Online is a collaborative online office suite. A stored cross-site scripting (XSS) vulnerability was found in Collabora Online prior to versions 22.05.13, 21.11.9.1, and 6.4.27. An attacker could create a document with an XSS payload as a document name. Later, if an administrator opened the admin console and navigated to the history page, the document name was injected as unescaped HTML and executed as a script inside the context of the admin console. The administrator JSON web token (JWT) used for the websocket connection could be leaked through this flaw. Users should upgrade to Collabora Online 22.05.13 or higher; Collabora Online 21.11.9.1 or higher; Collabora Online 6.4.27 or higher to receive a patch.

Severity
High
CVSS
8.7 (3.1)
Published
2023-05-31
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-79

Affected products

  • collaboraoffice / collabora_online

Showing 1 representative product identities from 3 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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