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CVE-2021-21973

VMware vCenter Server and Cloud Foundation Server Side Request Forgery (SSRF)

5.3 MEDIUMActively exploited (CISA KEV)EPSS 88.0%
  1. Published24 Feb 2021
  2. Added to CISA KEV7 Mar 2022
  3. Remediation due21 Mar 2022
Actively exploited (CISA KEV)

VMware vCenter Server and Cloud Foundation Server contain a SSRF vulnerability due to improper validation of URLs in a vCenter Server plugin. This allows for information disclosure.

Added to KEV: 7 Mar 2022Federal remediation due: 21 Mar 2022

Description

The vSphere Client (HTML5) contains an SSRF (Server Side Request Forgery) vulnerability due to improper validation of URLs in a vCenter Server plugin. A malicious actor with network access to port 443 may exploit this issue by sending a POST request to vCenter Server plugin leading to information disclosure. This affects: VMware vCenter Server (7.x before 7.0 U1c, 6.7 before 6.7 U3l and 6.5 before 6.5 U3n) and VMware Cloud Foundation (4.x before 4.2 and 3.x before 3.10.1.2).

CVSS 3.1 breakdown

Attack vectorNetwork
Attack complexityLow
Privileges requiredNone
User interactionNone
ScopeUnchanged
ConfidentialityLow
IntegrityNone
AvailabilityNone
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Affected products

VMware Cloud Foundation≥ 3.0 < 3.10.1.2 · ≥ 4.0 < 4.2
VMware Vcenter Server6.5 · 6.7 · 7.0

Remediation

Fixed in
VMware Cloud Foundation≥ 3.10.1.2

References

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Frequently asked

Is CVE-2021-21973 being actively exploited?

Yes. CVE-2021-21973 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added 7 Mar 2022.

How severe is CVE-2021-21973?

CVE-2021-21973 has a CVSS 3.1 base score of 5.3, rated medium. EPSS estimates a 88.0% probability of exploitation.

Which products are affected by CVE-2021-21973?

Affected products include VMware Cloud Foundation, VMware Vcenter Server.

How do I fix CVE-2021-21973?

Upgrade affected software to a fixed version, for example VMware Cloud Foundation 3.10.1.2 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2021-21973 against the real software inventory on every managed device, as each hourly inventory arrives. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. Because it is on the CISA KEV list, a risk for it never ranks below high, and the update that fixes it moves to the Emergency patch lane. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

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Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.