Vulnerabilities

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 1.8.16 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. More detailed information and general mitigation strategies may be found in the GitHub Security Advisory.

An Argument Injection issue in the plugin management of Etherpad 1.8.13 allows privileged users to execute arbitrary code on the server by installing plugins from an attacker-controlled source.

A Cross-Site Scripting (XSS) issue in the chat component of Etherpad 1.8.13 allows remote attackers to inject arbitrary JavaScript or HTML by importing a crafted pad.

In Etherpad < 1.8.3, a specially crafted URI would raise an unhandled exception in the cache mechanism and cause a denial of service (crash the instance).

In Etherpad UeberDB < 0.4.4, due to MySQL omitting trailing spaces on char / varchar columns during comparisons, retrieving database records using UeberDB's MySQL connector could allow bypassing access controls enforced on key names.

templates/pad.html in Etherpad-Lite 1.7.5 has XSS when the browser does not encode the path of the URL, as demonstrated by Internet Explorer.

Etherpad Lite before 1.6.4 is exploitable for admin access.

Etherpad 1.6.3 before 1.6.4 allows an attacker to execute arbitrary code.

node/hooks/express/apicalls.js in Etherpad Lite before v1.6.3 mishandles JSONP, which allows remote attackers to bypass intended access restrictions.

static/js/pad_utils.js in Etherpad Lite before v1.6.3 has XSS via window.location.href.