CVE-2021-21974
HIGH
8.8
CVSS Score
Published: February 24, 2021 at 04:57 PM UTC
Updated: June 17, 2026 at 03:36 AM UTC
2 products affected across 1 vendorCloud FoundationESXi
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Severity
HIGH8.8
Exploit prediction
EPSS 45%
SSVC
PoC
Description
OpenSLP as used in ESXi (7.0 before ESXi70U1c-17325551, 6.7 before ESXi670-202102401-SG, 6.5 before ESXi650-202102101-SG) has a heap-overflow vulnerability. A malicious actor residing within the same network segment as ESXi who has access to port 427 may be able to trigger the heap-overflow issue in OpenSLP service resulting in remote code execution.
Affected
Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.
3.0 ≤ v < 3.10.1.24 ≤ v < 4.24.0 ≤ v < 4.2
Affected range stops below 3.10.1.2, so it looks safe — our inference, not a vendor statement
Affected range stops below 4.2, so it looks safe — our inference, not a vendor statement
6.56.5 26.5 650-2017010016.5 650-2017030016.5 650-2017030026.5 650-2017040016.5 650-2017071016.5 650-2017071026.5 650-2017071036.5 650-2017072016.5 650-2017072026.5 650-2017072036.5 650-2017072046.5 650-2017072056.5 650-2017072066.5 650-2017072076.5 650-2017072086.5 650-2017072096.5 650-2017072106.5 650-2017072116.5 650-2017072126.5 650-2017072136.5 650-2017072146.5 650-2017072156.5 650-2017072166.5 650-2017072176.5 650-2017072186.5 650-2017072196.5 650-2017072206.5 650-2017072216.5 650-2017100016.5 650-2017120016.5 650-2018030016.5 650-2018060016.5 650-2018080016.5 650-2018100016.5 650-2018100026.5 650-2018110016.5 650-2018110026.5 650-2018113016.5 650-2019010016.5 650-2019030016.5 650-2019050016.5 650-2019080016.5 650-2019100016.5 650-201910040016.5 650-2019110016.5 650-2019114016.5 650-2019114026.5 650-2019120016.5 650-2019120026.5 650-2019121016.5 650-2019121026.5 650-2019121036.5 650-2019121046.5 650-2019123016.5 650-2019124016.5 650-2019124026.5 650-2019124036.5 650-2019124046.5 650-2020050016.5 650-2020060016.5 650-2020070016.5 650-2020100016.5 650-2020110016.5 650-2020110026.5 650-2021020016.5 before ESXi650-202102101-SG6.76.7 670-2018060016.7 670-2018070016.7 670-2018080016.7 670-2018100016.7 670-2018101016.7 670-2018101026.7 670-2018101036.7 670-2018102016.7 670-2018102026.7 670-2018102036.7 670-2018102046.7 670-2018102056.7 670-2018102066.7 670-2018102076.7 670-2018102086.7 670-2018102096.7 670-2018102106.7 670-2018102116.7 670-2018102126.7 670-2018102136.7 670-2018102146.7 670-2018102156.7 670-2018102166.7 670-2018102176.7 670-2018102186.7 670-2018102196.7 670-2018102206.7 670-2018102216.7 670-2018102226.7 670-2018102236.7 670-2018102246.7 670-2018102256.7 670-2018102266.7 670-2018102276.7 670-2018102286.7 670-2018102296.7 670-2018102306.7 670-2018102316.7 670-2018102326.7 670-2018102336.7 670-2018102346.7 670-2018110016.7 670-2019010016.7 670-2019014016.7 670-2019014026.7 670-2019014036.7 670-2019030016.7 670-2019040016.7 670-2019042016.7 670-201904201-ug6.7 670-2019042026.7 670-201904202-ug6.7 670-2019042036.7 670-201904203-ug6.7 670-2019042046.7 670-201904204-ug6.7 670-2019042056.7 670-201904205-ug6.7 670-2019042066.7 670-201904206-ug6.7 670-2019042076.7 670-201904207-ug6.7 670-2019042086.7 670-201904208-ug6.7 670-2019042096.7 670-201904209-ug6.7 670-2019042106.7 670-201904210-ug6.7 670-2019042116.7 670-201904211-ug6.7 670-2019042126.7 670-201904212-ug6.7 670-2019042136.7 670-201904213-ug6.7 670-2019042146.7 670-201904214-ug6.7 670-2019042156.7 670-201904215-ug6.7 670-2019042166.7 670-201904216-ug6.7 670-2019042176.7 670-201904217-ug6.7 670-2019042186.7 670-201904218-ug6.7 670-2019042196.7 670-201904219-ug6.7 670-2019042206.7 670-201904220-ug6.7 670-2019042216.7 670-201904221-ug6.7 670-2019042226.7 670-201904222-ug6.7 670-2019042236.7 670-201904223-ug6.7 670-2019042246.7 670-201904224-ug6.7 670-2019042256.7 670-201904225-ug6.7 670-2019042266.7 670-201904226-ug6.7 670-2019042276.7 670-201904227-ug6.7 670-2019042286.7 670-201904228-ug6.7 670-2019042296.7 670-201904229-ug6.7 670-2019050016.7 670-2019060026.7 670-2019081016.7 670-2019081026.7 670-2019081036.7 670-2019081046.7 670-2019082016.7 670-2019082026.7 670-2019082036.7 670-2019082046.7 670-2019082056.7 670-2019082066.7 670-2019082076.7 670-2019082086.7 670-2019082096.7 670-2019082106.7 670-2019082116.7 670-2019082126.7 670-2019082136.7 670-2019082146.7 670-2019082156.7 670-2019082166.7 670-2019082176.7 670-2019082186.7 670-2019082196.7 670-2019082206.7 670-2019082216.7 670-2019120016.7 670-2019121016.7 670-2019121026.7 670-2019124016.7 670-2019124026.7 670-2019124036.7 670-2019124046.7 670-2019124056.7 670-2020040016.7 670-2020040026.7 670-2020043016.7 670-2020044016.7 670-2020044026.7 670-2020044036.7 670-2020044046.7 670-2020044056.7 670-2020044066.7 670-2020044076.7 670-2020044086.7 670-2020060016.7 670-2020080016.7 670-2020100016.7 670-2020110016.7 670-2020110026.7 670-2021020016.7 before ESXi670-202102401-SG7.0 before ESXi70U1c-173255517.0.07.0.0 b7.0.0 update_17.0.0 update_1a7.0.0 update_1b
Remediation
No guide yetNo remediation guidance has been written for this CVE yet. What the record does show:
Patch and advisory references
References (3)
x_refsource_MISCExploitThird Party AdvisoryVDB Entry
Source: [email protected]
http://packetstormsecurity.com/files/162957/VMware-ESXi-OpenSLP-Heap-Overflow.htmlx_refsource_CONFIRMVendor Advisory
Source: [email protected]
https://www.vmware.com/security/advisories/VMSA-2021-0002.htmlx_refsource_MISCThird Party AdvisoryVDB Entry
Source: [email protected]
https://www.zerodayinitiative.com/advisories/ZDI-21-250/SSVC — Action Prioritization
SSVCPoCNot automatableTotal impact
SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.
CVSS
8.8HIGHCISA-ADP
- Attack Vector
- ADJACENT_NETWORK
- Complexity
- LOW
- Privileges
- NONE
- User Interaction
- NONE
- Scope
- UNCHANGED
- Confidentiality
- HIGH
- Integrity
- HIGH
- Availability
- HIGH
Vector?
Quick Info
StatusMODIFIED
CWE
CWE-787
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