CVE-2020-3992: VMware ESXi OpenSLP Use-After-Free Vulnerability

CVSS: 10.0v2.0HighKEVRansomwareAnalyzed

Published 20-10-2020Last modified 12-08-2026

Vulnerability summary

CVE-2020-3992 is a high (CVSS 10.0) Use After Free vulnerability in VMware ESXi. It is known to be exploited: CISA lists it, first on 03-11-2021. It has been used in ransomware campaigns. EPSS estimates a 83.02% chance of exploitation in the next 30 days, higher than 99.6% of scored vulnerabilities.

Overall risk

90/100

0100

Critical · default modelHow is this calculated?

CVSS score

10.0/10

010

High · v2.0 (NVD)

EPSS score

83.02%

0%100%

Critical · 0.00 pp in 30 days

KEVListedCISA

RansomwareKnown useFlagged by CISA

Public exploits0No public exploits recorded

Timeline

20-10-2020
PublishedVulnerability first disclosed.
03-11-2021
Added to CISA KEVVMware ESXi OpenSLP Use-After-Free Vulnerability
03-05-2022
CISA remediation dueApply updates per vendor instructions.
12-08-2026
Last modifiedVulnerability information updated.

Description

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.

CVSS metrics

3 scores · 2 sources · 2 versions

v3.19.8v2.010.0

EPSS trend

Probability

83.02%

Chance of exploitation in the next 30 days

Percentile

100%

Versus all other CVEs

30-day change

0.00 pp

From 83.02% on 20-09-2026

20-09-202620-10-2026

EPSS score

83.02%

Known exploited

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CISA KEVListed

Added: 03-11-2021
Federal due date: 03-05-2022

CISA required action

Apply updates per vendor instructions. nvd.nist.gov/vuln/detail/CVE-2020-3992

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

CWE-416Use After FreeThe product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.

Affected systems

Vmware2 products

cloud_foundation≥ 3.0, < 3.10.1.2 | ≥ 4.0, < 4.1.0.1
esxiEOL6.5 | 6.5:2 | 6.5:650-201701001 | 6.5:650-201703001 | 6.5:650-201703002 | 6.5:650-201704001 | 6.5:650-201707101 | 6.5:650-201707102 | 6.5:650-201707103 | 6.5:650-201707201 | 6.5:650-201707202 | 6.5:650-201707203 | 6.5:650-201707204 | 6.5:650-201707205 | 6.5:650-201707206 | 6.5:650-201707207 | 6.5:650-201707208 | 6.5:650-201707209 | 6.5:650-201707210 | 6.5:650-201707211 | 6.5:650-201707212 | 6.5:650-201707213 | 6.5:650-201707214 | 6.5:650-201707215 | 6.5:650-201707216 | 6.5:650-201707217 | 6.5:650-201707218 | 6.5:650-201707219 | 6.5:650-201707220 | 6.5:650-201707221 | 6.5:650-201710001 | 6.5:650-201712001 | 6.5:650-201803001 | 6.5:650-201806001 | 6.5:650-201808001 | 6.5:650-201810001 | 6.5:650-201810002 | 6.5:650-201811001 | 6.5:650-201811002 | 6.5:650-201811301 | 6.5:650-201901001 | 6.5:650-201903001 | 6.5:650-201905001 | 6.5:650-201908001 | 6.5:650-201910001 | 6.5:650-20191004001 | 6.5:650-201911001 | 6.5:650-201911401 | 6.5:650-201911402 | 6.5:650-201912001 | 6.5:650-201912002 | 6.5:650-201912101 | 6.5:650-201912102 | 6.5:650-201912103 | 6.5:650-201912104 | 6.5:650-201912301 | 6.5:650-201912401 | 6.5:650-201912402 | 6.5:650-201912403 | 6.5:650-201912404 | 6.5:650-202005001 | 6.5:650-202006001 | 6.5:650-202007001 | 6.5:650-202010001 | 6.7 | 6.7:670-201806001 | 6.7:670-201807001 | 6.7:670-201808001 | 6.7:670-201810001 | 6.7:670-201810101 | 6.7:670-201810102 | 6.7:670-201810103 | 6.7:670-201810201 | 6.7:670-201810202 | 6.7:670-201810203 | 6.7:670-201810204 | 6.7:670-201810205 | 6.7:670-201810206 | 6.7:670-201810207 | 6.7:670-201810208 | 6.7:670-201810209 | 6.7:670-201810210 | 6.7:670-201810211 | 6.7:670-201810212 | 6.7:670-201810213 | 6.7:670-201810214 | 6.7:670-201810215 | 6.7:670-201810216 | 6.7:670-201810217 | 6.7:670-201810218 | 6.7:670-201810219 | 6.7:670-201810220 | 6.7:670-201810221 | 6.7:670-201810222 | 6.7:670-201810223 | 6.7:670-201810224 | 6.7:670-201810225 | 6.7:670-201810226 | 6.7:670-201810227 | 6.7:670-201810228 | 6.7:670-201810229 | 6.7:670-201810230 | 6.7:670-201810231 | 6.7:670-201810232 | 6.7:670-201810233 | 6.7:670-201810234 | 6.7:670-201811001 | 6.7:670-201901001 | 6.7:670-201901401 | 6.7:670-201901402 | 6.7:670-201901403 | 6.7:670-201903001 | 6.7:670-201904001 | 6.7:670-201904201 | 6.7:670-201904201-ug | 6.7:670-201904202 | 6.7:670-201904202-ug | 6.7:670-201904203 | 6.7:670-201904203-ug | 6.7:670-201904204 | 6.7:670-201904204-ug | 6.7:670-201904205 | 6.7:670-201904205-ug | 6.7:670-201904206 | 6.7:670-201904206-ug | 6.7:670-201904207 | 6.7:670-201904207-ug | 6.7:670-201904208 | 6.7:670-201904208-ug | 6.7:670-201904209 | 6.7:670-201904209-ug | 6.7:670-201904210 | 6.7:670-201904210-ug | 6.7:670-201904211 | 6.7:670-201904211-ug | 6.7:670-201904212 | 6.7:670-201904212-ug | 6.7:670-201904213 | 6.7:670-201904213-ug | 6.7:670-201904214 | 6.7:670-201904214-ug | 6.7:670-201904215 | 6.7:670-201904215-ug | 6.7:670-201904216 | 6.7:670-201904216-ug | 6.7:670-201904217 | 6.7:670-201904217-ug | 6.7:670-201904218 | 6.7:670-201904218-ug | 6.7:670-201904219 | 6.7:670-201904219-ug | 6.7:670-201904220 | 6.7:670-201904220-ug | 6.7:670-201904221 | 6.7:670-201904221-ug | 6.7:670-201904222 | 6.7:670-201904222-ug | 6.7:670-201904223 | 6.7:670-201904223-ug | 6.7:670-201904224 | 6.7:670-201904224-ug | 6.7:670-201904225 | 6.7:670-201904225-ug | 6.7:670-201904226 | 6.7:670-201904226-ug | 6.7:670-201904227 | 6.7:670-201904227-ug | 6.7:670-201904228 | 6.7:670-201904228-ug | 6.7:670-201904229 | 6.7:670-201904229-ug | 6.7:670-201905001 | 6.7:670-201906002 | 6.7:670-201908101 | 6.7:670-201908102 | 6.7:670-201908103 | 6.7:670-201908104 | 6.7:670-201908201 | 6.7:670-201908202 | 6.7:670-201908203 | 6.7:670-201908204 | 6.7:670-201908205 | 6.7:670-201908206 | 6.7:670-201908207 | 6.7:670-201908208 | 6.7:670-201908209 | 6.7:670-201908210 | 6.7:670-201908211 | 6.7:670-201908212 | 6.7:670-201908213 | 6.7:670-201908214 | 6.7:670-201908215 | 6.7:670-201908216 | 6.7:670-201908217 | 6.7:670-201908218 | 6.7:670-201908219 | 6.7:670-201908220 | 6.7:670-201908221 | 6.7:670-201912001 | 6.7:670-201912101 | 6.7:670-201912102 | 6.7:670-201912401 | 6.7:670-201912402 | 6.7:670-201912403 | 6.7:670-201912404 | 6.7:670-201912405 | 6.7:670-202004001 | 6.7:670-202004002 | 6.7:670-202004301 | 6.7:670-202004401 | 6.7:670-202004402 | 6.7:670-202004403 | 6.7:670-202004404 | 6.7:670-202004405 | 6.7:670-202004406 | 6.7:670-202004407 | 6.7:670-202004408 | 6.7:670-202006001 | 6.7:670-202008001 | 6.7:670-202010001 | 7.0.0 | 7.0.0:1.20.16321839

1 vendor · 2 products

References

4 links

www.vmware.com/security/advisories/VMSA-2020-0023.htmlX Refsource MISCPatchVendor Advisory
www.zerodayinitiative.com/advisories/ZDI-20-1377/X Refsource MISCThird Party AdvisoryVDB Entry
www.zerodayinitiative.com/advisories/ZDI-20-1385/X Refsource MISCThird Party AdvisoryVDB Entry
www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-3992Government ResourceUS Government Resource

Vulnerability summary

Timeline

Description

CVSS metrics

EPSS trend

Known exploited

Public exploits

Weaknesses

Affected systems

References

Related vulnerabilities