Asterisk Security Team
2018-Feb-21 21:57 UTC
[asterisk-users] AST-2018-006: WebSocket frames with 0 sized payload causes DoS
Asterisk Project Security Advisory - AST-2018-006
Product Asterisk
Summary WebSocket frames with 0 sized payload causes DoS
Nature of Advisory Denial of Service
Susceptibility Remote Unauthenticated Sessions
Severity Moderate
Exploits Known No
Reported On February 05, 2018
Reported By Sean Bright
Posted On February 21, 2018
Last Updated On February 21, 2018
Advisory Contact bford AT digium DOT com
CVE Name CVE-2018-7287
Description When reading a websocket, the length was not being checked.
If a payload of length 0 was read, it would result in a
busy loop that waited for the underlying connection to
close.
Resolution A patch to asterisk is available that checks for payloads of
size 0 before attempting to read them. By default, Asterisk
does not enable the HTTP server, which means it is not
vulnerable to this problem. If the HTTP server is enabled,
you can disable it if you do not need it. Otherwise, the
patch provided with this security vulnerability can be
applied. Either of these approaches will resolve the
problem.
Affected Versions
Product Release
Series
Asterisk Open Source 15.x All versions
Corrected In
Product Release
Asterisk Open Source 15.2.2
Patches
SVN URL Revision
http://downloads.asterisk.org/pub/security/AST-2018-006-15.diff Asterisk
15
Links https://issues.asterisk.org/jira/browse/ASTERISK-27658
http://downloads.asterisk.org/pub/security/AST-2018-006.html
Asterisk Project Security Advisories are posted at
http://www.asterisk.org/security
This document may be superseded by later versions; if so, the latest
version will be posted at
http://downloads.digium.com/pub/security/AST-2018-006.pdf and
http://downloads.digium.com/pub/security/AST-2018-006.html
Revision History
Date Editor Revisions Made
February 15, 2018 Ben Ford Initial Revision
February 21, 2018 Ben Ford Added CVE Name
Asterisk Project Security Advisory - AST-2018-006
Copyright ?? 2018 Digium, Inc. All Rights Reserved.
Permission is hereby granted to distribute and publish this advisory in its
original, unaltered form.