CVE-2021-42079Public exploitNetwork attack vector

Authenticated SSRF via unrestricted alert webhook URLs

Published Jul 10, 2023 · Updated Sep 22, 2025

Server-side request forgery in OSNEXUS QuantaStor before 6.0.0.355 allows remote authenticated users to send POST requests to arbitrary hosts. The alert configuration API accepts attacker-controlled Slack or Mattermost webhook URLs, and raising an alert passes generated JSON to curl without restricting the destination. Administrator privileges are required, and the demonstrated consequence is an appliance-originated POST request to an attacker-chosen destination.

CVSS severity6.2
Medium
EPSS probability0.69%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Server-side request forgery in OSNEXUS QuantaStor before 6.0.0.355 allows remote authenticated users to send POST requests to arbitrary hosts. The alert configuration API accepts attacker-controlled Slack or Mattermost webhook URLs, and raising an alert passes generated JSON to curl without restricting the destination. Administrator privileges are required, and the demonstrated consequence is an appliance-originated POST request to an attacker-chosen destination.

The record

CVE
CVE-2021-42079
Published
Jul 10, 2023
Updated
Sep 22, 2025
Vendor
OSNEXUS
Product
QuantaStor
Classifications
CWE-918, T1090
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 10, 2023CVE publishedPublication date reported by the CVE source.
  2. Sep 22, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <6.0.0.355

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

OSNEXUS · QuantaStorversion=0 <6.0.0.355

Published CVSS scores

6.2Dutch Institute for Vulnerability DisclosureCVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:N/A:N
4.9NIST National Vulnerability DatabaseCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-918Server-Side Request Forgery (SSRF)
T1090Proxy

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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