cvedb.io
CVE-2021-43802
CRITICAL · CVSS 9.9
EPSS exploitation probability: 0%
Published 2021-12-09T23:15:07.517 · Last modified 2026-06-17T04:11:28.070

Summary

Etherpad is a real-time collaborative editor. In versions prior to 1.8.16, an attacker can craft an `*.etherpad` file that, when imported, might allow the attacker to gain admin privileges for the Etherpad instance. This, in turn, can be used to install a malicious Etherpad plugin that can execute arbitrary code (including system commands). To gain privileges, the attacker must be able to trigger deletion of `express-session` state or wait for old `express-session` state to be cleaned up. Core Etherpad does not delete any `express-session` state, so the only known attacks require either a plugin that can delete session state or a custom cleanup process (such as a cron job that deletes old `sessionstorage:*` records). The problem has been fixed in version 1.8.16. If users cannot upgrade to

Affected products

etherpad — etherpad

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.