1333225 - Blocklist WebEx add-ons with public remote-code execution vulnerability

Status: RESOLVED FIXED

(Toolkit :: Blocklist Policy Requests, defect)

Description

[Daniel Veditz [:dveditz]]

Tavis Ormandy just tweeted about a bug in the Chrome version of the WebEx Extension that allows RCE from any page that includes a magic string in its URL.

https://twitter.com/taviso/status/823642226093760512

The tweet links to the Project Zero bug which is now public and contains the script your page could need to include to execute shell commands on the client's machine. Searching DXR it appears we have at least 5 add-ons that contain this magic string. Have not searched to see if there are other WebEx add-ons that use a different Firefox-specific url but that would seem unlikely (if they're the same then they don't need to UA sniff to serve the right page).

Comment 1

[Daniel Veditz [:dveditz]]

For those with access:
https://dxr.mozilla.org/addons/search?q=cwcsf-nativemsg-iframe-43c85c0d-d633-af5e-c056-32dc7efc570b

Comment 2

[Daniel Veditz [:dveditz]]

in our repo I find

https://dxr.mozilla.org/addons/source/addons/735601/
 id:  [e-mail]
 ver: 1.0.1

https://dxr.mozilla.org/addons/source/addons/735588
 id:  [e-mail]
 ver: 1.0.0

https://dxr.mozilla.org/addons/source/addons/735573
 id:  [e-mail]
 ver: 1.0.0

https://dxr.mozilla.org/addons/source/addons/730787
 id:  [e-mail]
 ver: 1.0.1

https://dxr.mozilla.org/addons/source/addons/728001
 id:  [e-mail]
 ver: 1.0.0

Comment 3

[Andrew McCreight [:mccr8]]

The first one looks like it is the Cisco WebEx Extension on AMO, judging by the id number thing.
  https://addons.mozilla.org/en-US/firefox/addon/cisco-webex-extension/?src=search

Comment 4

[Jorge Villalobos [:jorgev] (he/him)]

Blocked: https://addons.mozilla.org/en-US/firefox/blocked/i1522

Comment 5

[April King [:April]]

Thanks for the quick turnaround.