[IT-SecNots] [MediaWiki-announce] Parsoid Security Update and Release

[Subramanya Sastry <ssastry AT wikimedia.org>]

The parsing team has fixed a security bug in Parsoid [1].

* Users could send invalid prefixes, formats, or domains and run
  javascript code on the error page that Parsoid displayed.

* This fix has been applied to the Wikimedia cluster [2] and also merged
  into Parsoid master [1].

* We have also released a 0.5.3 deb version with this patch applied. [3]

* We have also released a 0.5.3 npm version of Parsoid. [4]

* Parsoid is a stateless service and doesn't retain any state between
  requests. In private wikis, VisualEditor can be configured to
  forward the user cookie to Parsoid to pass along to the MediaWiki API
  to parse a page, but this exploit is not exposed through VE.

  In addition, Parsoid doesn't receive any user credentials on
  public wikis.

* However, if a wiki's Parsoid service is publicly accessible on the
  internet *and* is accessible through the wiki's domain, then, this
  exploit can be used to leak user cookies for that wiki. For all wikis
  that use Parsoid in this fashion, we recommend they patch their
  Parsoid installation immediately.

* On the Wikimedia cluster, Parsoid is proxied behind RESTBase and is
  not public accessible and as such, this exploit wasn't available for
  an exploit to steal user sessions.

Thanks to the reporter of this exploit, Darian Patrick from the
Security Team, Arlo Breault from the Parsing Team, Daniel Zahn and
others from Ops for their assistance handling this bug and preparing
this release.

Subramanya Sastry,
Technical Lead and Manager,
Parsing Team,
Wikimedia Foundation.


[1] https://gerrit.wikimedia.org/r/#/c/319115
[2] 
https://www.mediawiki.org/wiki/Parsoid/Deployments#Monday.2C_October_31.2C_2016_around_1:15_PT:_Y.C2.A0Deployed_e503e801
[3] https://releases.wikimedia.org/debian/pool/main/p/parsoid/
[4] https://www.npmjs.com/package/parsoid


_______________________________________________
MediaWiki announcements mailing list
To unsubscribe, go to:
https://lists.wikimedia.org/mailman/listinfo/mediawiki-announce