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CVE-2021-21973· NVD / CVE Program· CNA vmware

The vSphere Client (HTML5) contains an SSRF (Server Side Request Forgery) vulnerability due to improper validation of URLs in a vCenter Serv

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).

MediumCVSS 5.3 · v3.1KEVWeaponized No fix recorded
Published
Feb 24, 2021
Updated
Jun 16, 2026
EPSS
87.6% · 100th percentile
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Report tools

JSON

Action score

77

This week

Don’t wait for the next maintenance window.

CVSS
21 / 40 · 5.3 / 10
CISA KEV
30 / 30 · Listed
EPSS
26 / 30 · 87.6%

CISA SSVC decision

Exploitation
active
Automatable
yes
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

Actively exploited in the wild

CISA added this to its Known Exploited Vulnerabilities catalog on Mar 7, 2022. That signals real attacks, not theory.

Remediation deadline for government agencies: Mar 21, 2022.

Affected systems

VendorProduct
vmwarecloud foundation
vmwarevcenter server

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • vmware cloud foundation3.0 and later · before 3.10.1.2
  • vmware cloud foundation4.0 and later · before 4.2
  • vmware vcenter server6.5
  • vmware vcenter server6.7
  • vmware vcenter server7.0

Versions reported by the vendor

Affected version ranges reported by the assigning authority (vmware). Independent of NVD's CPE analysis and usually ahead of it.

  • n/a VMware Cloud Foundation

    • 4.x before 4.2, 3.x before 3.10.1.2affected

  • n/a VMware vCenter Server

    • 7.x before 7.0 U1c, 6.7 before 6.7 U3l, 6.5 before 6.5 U3naffected

Same product

vmware: all records

Other highest-scoring records for the same primary product.

  • CVE-2021-22005The vCenter Server contains an arbitrary file upload vulnerability in the Analytics service.KEV
    99Now
  • CVE-2021-21972The vSphere Client (HTML5) contains a remote code execution vulnerability in a vCenter Server plugin.KEV
    99Now
  • CVE-2020-3992OpenSLP as used in VMware ESXi (7.0 before ESXi_7.0.1-0.0.16850804, 6.7 before ESXi670-202010401-SG, 6.5 before ESXi650-202010401-SG) has a KEV
    94Now
  • CVE-2024-38812Heap-overflow vulnerabilityKEV
    85Now
  • CVE-2021-21975Server Side Request Forgery in vRealize Operations Manager API (CVE-2021-21975) prior to 8.4 may allow a malicious actor with network accessKEV
    83Now
  • CVE-2024-37079vCenter Server contains a heap-overflow vulnerability in the implementation of the DCERPC protocol.KEV
    76This week

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

No fix version is recorded for this entry. Check the references for vendor advisories.

Exploit status

Weaponized

A ready exploit tool or active in-the-wild use is known for this vulnerability. This should be your top priority.

Evidence

  • Nuclei detection template ×1
  • Proof-of-concept repository on GitHub ×1

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
SourceKindDate
Nuclei detection templateNuclei template CVE-2021-21973 —
Proof-of-concept repository on GitHubstars:12021-03-16

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

  1. Published
  2. First PoC+19 d
  3. CISA KEV+375 d
  4. TodaySep 29, 2026+2043 d
EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
low · data can be read
Integrity
none
Availability
none
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
Low
Integrity impact
None
Availability impact
None

Weakness class (CWE)

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

CVSS vector

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

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

Noroxi analysis

No Noroxi analysis for this record yet

We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.

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Change log

No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.

References

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records