Privilege Escalation Affecting ep_etherpad-lite package, versions *


Severity

Recommended
0.0
high
0
10

CVSS assessment made by Snyk's Security Team. Learn more

Threat Intelligence

EPSS
0.13% (50th percentile)

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  • Snyk IDSNYK-JS-EPETHERPADLITE-2314881
  • published10 Dec 2021
  • disclosed10 Dec 2021
  • creditUnknown

Introduced: 10 Dec 2021

CVE-2021-43802  (opens in a new tab)
CWE-264  (opens in a new tab)

How to fix?

A fix was pushed into the master branch but not yet published.

Overview

ep_etherpad-lite is a modern really-real-time collaborative document editor.

Affected versions of this package are vulnerable to Privilege Escalation. 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).

If users cannot upgrade to the fixed version or install patches manually, several workarounds are available. Users may configure their reverse proxies to reject requests to /p/*/import, which will block all imports, not just *.etherpad imports; limit all users to read-only access; and/or prevent the reuse of express_sid cookie values that refer to deleted express-session state.

CVSS Scores

version 3.1