CVE-2023-34939 — Onlyoffice Community Server before v12

Onlyoffice Community Server before v12.5.2 was discovered to contain a remote code execution (RCE) vulnerability via the component UploadProgress.ashx.

01What is this vulnerability?

Onlyoffice Community Server before v12.5.2 was discovered to contain a remote code execution (RCE) vulnerability via the component UploadProgress.ashx.

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

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2023-06-22T00:00:00.000Z
• Last modified: 2024-12-06T18:25:18.641Z

09References

• github.com — https://github.com/firsov/onlyoffice
• github.com — https://github.com/ONLYOFFICE/CommunityServer/blob/master/CHANGELOG.md#version-1…
• github.com — https://github.com/firsov/onlyoffice/blob/main/CVE-2023-34939-PoC.md