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CVE-2021-21972· NVD / CVE Program· CNA vmware

The vSphere Client (HTML5) contains a remote code execution vulnerability in a vCenter Server plugin.

The vSphere Client (HTML5) contains a remote code execution vulnerability in a vCenter Server plugin. A malicious actor with network access to port 443 may exploit this issue to execute commands with unrestricted privileges on the underlying operating system that hosts vCenter Server. 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).

CriticalCVSS 9.8 · v3.1KEVWeaponized No fix recorded
Published
Feb 24, 2021
Updated
Aug 12, 2026
EPSS
99.9% · 100th percentile
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Report tools

JSON

Action score

99

Now

Patch today or shut off access.

CVSS
39 / 40 · 9.8 / 10
CISA KEV
30 / 30 · Listed
EPSS
30 / 30 · 99.9%

CISA SSVC decision

Exploitation
active
Automatable
yes
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

Actively exploited in the wild

CISA added this to its Known Exploited Vulnerabilities catalog on Nov 3, 2021. That signals real attacks, not theory.

Remediation deadline for government agencies: Nov 17, 2021.

Known to be used in ransomware campaigns.

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-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-2021-21973The vSphere Client (HTML5) contains an SSRF (Server Side Request Forgery) vulnerability due to improper validation of URLs in a vCenter ServKEV
    77This week
  • 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

  • Metasploit module ×1
  • Exploit-DB entry ×2
  • Nuclei detection template ×1
  • Proof-of-concept repository on GitHub ×27

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
Exploit-DB entrywebapps2021-06-24
Exploit-DB entrywebapps2021-03-01
Metasploit moduleexploit/multi/http/vmware_vcenter_uploadova_rceVMware vCenter Server Unauthenticated OVA File Upload RCEexploit2021-02-23
Nuclei detection templateNuclei template CVE-2021-21972 —
Proof-of-concept repository on GitHubstars:1622020-03-11
Proof-of-concept repository on GitHubstars:1352021-02-24
Proof-of-concept repository on GitHubstars:4962021-02-24
Proof-of-concept repository on GitHubstars:82021-02-24
Proof-of-concept repository on GitHubstars:2682021-02-24
Proof-of-concept repository on GitHubstars:12021-02-25
Proof-of-concept repository on GitHubstars:542021-02-25
Proof-of-concept repository on GitHubstars:332021-02-25

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. First PoC-351 d
  2. Metasploit-2 d
  3. Published
  4. CISA KEV+251 d
  5. 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
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-22 · Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

CVSS vector

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

nvd-primary

Root cause

A user-supplied file name is joined with the allowed directory, but the result is never checked to confirm it is still inside that directory.

The bug in code

The whole CWE-22 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

ts
const file = path.join(ROOT, req.query.name);res.sendFile(file);

Fixed

ts
const file = path.resolve(ROOT, req.query.name);if (!file.startsWith(ROOT + path.sep)) {  return res.sendStatus(400);}res.sendFile(file);

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.

We use this product, ask for help

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