Il giorno 10 dicembre 2014, il Team di Sviluppo di Asterisk ha annunciato il rilascio di AST-2014-019: Remote Crash Vulnerability in WebSocket Server.
Dal post originale:
sterisk Project Security Advisory - AST-2014-019
Summary Remote Crash Vulnerability in WebSocket Server
Nature of Advisory Denial of Service
Susceptibility Remote Unauthenticated Sessions
Exploits Known No
Reported On 30 October 2014
Reported By Badalian Vyacheslav
Posted On 10 December 2014
Last Updated On December 10, 2014
Advisory Contact Joshua Colp
Description When handling a WebSocket frame the res_http_websocket
module dynamically changes the size of the memory used to
allow the provided payload to fit. If a payload length of
zero was received the code would incorrectly attempt to
resize to zero. This operation would succeed and end up
freeing the memory but be treated as a failure. When the
session was subsequently torn down this memory would get
freed yet again causing a crash.
Users of the WebSocket functionality also did not take into
account that provided text frames are not guaranteed to be
NULL terminated. This has been fixed in chan_sip and
chan_pjsip in the applicable versions.
Resolution Ensure the built-in HTTP server is disabled, upgrade to a
version listed below, or apply the applicable patch.
The change ensures that res_http_websocket does not treat
the freeing of memory when a payload length of zero is
received as fatal.
Certified Asterisk 11.6 All versions
Asterisk Open Source 11.x All versions
Asterisk Open Source 12.x All versions
Asterisk Open Source 13.x All versions
Certified Asterisk 11.6-cert9
Asterisk Open Source 11.14.2, 12.7.2, 13.0.2
SVN URL Revision
Asterisk Project Security Advisories are posted at
This document may be superseded by later versions; if so, the latest
version will be posted at