NVD / CVE Program· CNA vmware

CVE-2020-3992: OpenSLP 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…

CriticalCVSS 9.8 · v3.1KEVWeaponized No fix recorded

Noroxi assessment

Priority: Now (action score 94/100)

CISA has confirmed exploitation in the wild (Nov 3, 2021); it is known to be used in ransomware campaigns. Remediation deadline for US federal agencies: May 3, 2022.
Probability of exploitation in the next 30 days: 83% (FIRST EPSS); higher than 99.6% of all records.
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.
According to CISA the attack is automatable: targets can be found by mass scanning.
According to the record, no fixed version is available yet.
Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Patch today or shut off access. Until a fix is released, restrict access to the affected component and follow the vendor's advisory.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · CISA KEV · FIRST EPSS

OpenSLP 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 use-after-free issue. A malicious actor residing in the management network who has access to port 427 on an ESXi machine may be able to trigger a use-after-free in the OpenSLP service resulting in remote code execution.

BDU:2020-04911

Published: Oct 20, 2020
Updated: Aug 12, 2026
EPSS: 83.0% · 99th percentile
CWE: CWE-416

Report tools

JSON

Action score

Now

Patch today or shut off access.

CVSS: 39 / 40 · 9.8 / 10
CISA KEV: 30 / 30 · Listed
EPSS: 25 / 30 · 83.0%

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 US federal agencies: May 3, 2022.

Known to be used in ransomware campaigns.

Get told when this record changes

In CISA KEV: exploitation in the wild confirmed
Weaponized exploit exists
No fixed version yet

If any of these changes, we'll tell you in the daily email digest.

Is your version affected? Check it

Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

Vendor	Product	CPE
vmware	cloud foundation	cpe:2.3:a:vmware:cloud_foundation
vmware	esxi	cpe:2.3:o:vmware:esxi

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 ESXi
- VMware ESXi (7.0 before ESXi_7.0.1-0.0.16850804, 6.7 before ESXi670-202010401-SG, 6.5 before ESXi650-202010401-SG)affected

Affected versions · NVD (5)

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 4.1.0.1
vmware esxi6.5
vmware esxi6.7
vmware esxi7.0.0

Same product

vmware: all records

Other highest-scoring records for the same primary product.

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CVE-2021-21972The vSphere Client (HTML5) contains a remote code execution vulnerability in a vCenter Server plugin.KEV
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CVE-2024-38812Heap-overflow vulnerabilityKEV
85Now

Published before and after this one in the same product

← EarlierCVE-2020-3976Aug 21, 2020 · VMware ESXi and vCenter Server contain a partial denial of service vulnerability in their respective authentication services.
22Monitor
← EarlierCVE-2020-3981Oct 20, 2020 · VMware ESXi (7.0 before ESXi_7.0.1-0.0.16850804, 6.7 before ESXi670-202008101-SG, 6.5 before ESXi650-202007101-SG), Workstation (15.x)…
23Monitor
Later →CVE-2020-3993Oct 20, 2020 · VMware NSX-T (3.x before 3.0.2, 2.5.x before 2.5.2.2.0) contains a security vulnerability that exists in the way it allows a KVM host to…
23Monitor

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

Proof-of-concept repository on GitHub ×2

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
Source	Kind	Date
Proof-of-concept repository on GitHub	stars:50	2020-12-01
Proof-of-concept repository on GitHub	stars:68	2021-02-04

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.

PublishedOct 20, 2020
First PoCDec 1, 2020+41 d
CISA KEVNov 3, 2021+378 d
TodayNov 14, 2026+2216 d

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

TR-20-880 · Oct 22, 2020(VMware Zafiyeti)

All national notices →

Not on record for this CVE: EPSS history · patch commit or PR link · researcher credit · variant or chain candidate · public bounty program.

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-416 · Use After Free

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

After a memory region is freed, another reference pointing to it is still used. By then, the same region may have been allocated for different data.

The bug in code

The whole CWE-416 class

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

Vulnerable

1free(dev->buf);
2/* ... another thread is still running ... */
3process(dev->buf);

Fixed

1lock(&dev->lock);
2free(dev->buf);
3dev->buf = NULL;
4unlock(&dev->lock);

Attack context

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

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log (0)

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

References

www.vmware.com/security/advisories/VMSA-2020-0023.html

Show all references (3 more)

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

All records