CVE-2023-50883 — ONLYOFFICE Docs before 8

ONLYOFFICE Docs before 8.0.1 allows XSS because a macro is an immediately-invoked function expression (IIFE), and therefore a sandbox escape is possible by directly calling the constructor of the Function object. NOTE: this issue exists because of an incorrect fix for CVE-2021-43

01What is this vulnerability?

ONLYOFFICE Docs before 8.0.1 allows XSS because a macro is an immediately-invoked function expression (IIFE), and therefore a sandbox escape is possible by directly calling the constructor of the Function object. NOTE: this issue exists because of an incorrect fix for CVE-2021-43446.

02Affected products

Vendor	Product	Versions
n	a / n/a	n/a

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

08Timeline

• Published: 2024-09-09T00:00:00.000Z
• Last modified: 2024-09-10T14:24:40.310Z

09References

• www.onlyoffice.com — https://www.onlyoffice.com/
• www.syss.de — https://www.syss.de/fileadmin/dokumente/Publikationen/Advisories/SYSS-2023-027.t…
• www.syss.de — https://www.syss.de/pentest-blog/cross-site-scripting-schwachstelle-in-onlyoffic…