Home/CVE/OpenSLP as used in ESXi (7.0 before ESXi70U1c-17325551, 6.7 before ESXi670-202102401-SG, 6.5 before ESXi650-202102101-SG
CVE

CVE-2021-21974

OpenSLP as used in ESXi (7.0 before ESXi70U1c-17325551, 6.7 before ESXi670-202102401-SG, 6.5 before ESXi650-202102101-SG

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.

HIGH · CVSS 8.8 EPSS 0.557
Act now
  • EPSS ≥ 0.50 - high probability of exploitation in the next 30 days
  • EPSS percentile: top 2% of all CVEs by exploitation likelihood
  • Public exploit or PoC is available
  • CVSS base score ≥ 7.0
Sigma rules8 YARA rules0
⬡

Weakness Classification

CWE-787Out-of-bounds Write
▤

Affected Products & Versions

3
vmware cloud foundation>= 3.0 and < 3.10.1.2
vmware cloud foundation>= 4.0 and < 4.2
vmware esxiall versions
⚠

Public Exploits & PoCs

1
pocpacketstormsecurity.com · VMware-ESXi-OpenSLP-Heap-Overflow.htmlpacketstormsecurity.com
◈

Detection Rules (IDS/IPS)

1
et-openET EXPLOIT VMWare ESXi 6.7.0 OpenSLP Remote Code Execution Attempt - Directory Agent Advertisement Heap Overflow (CVE-2021-21974)attempted-admin
Open rulesets (ET Open, Snort Community, abuse.ch) link to source. Commercial rulesets are reference-only.
◈

Sigma Hunt Rules

8
Exact rules name this CVE ID. Product rules name an affected product in their title. Related rules cover techniques used by actors who exploited this CVE. Showing the most relevant matches; the complete related set is on the full drill-down.
producthighESXi Admin Permission Assigned To Account Via ESXCLI
productmediumESXi Storage Information Discovery Via ESXCLI
productmediumESXi Network Configuration Discovery Via ESXCLI
productmediumESXi VSAN Information Discovery Via ESXCLI
productmediumESXi System Information Discovery Via ESXCLI
productmediumESXi VM Kill Via ESXCLI
▣

Scoring & Timeline

8.8
HIGH · CVSS v3.1 · security@vmware.com
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD24 Feb 2021 · 05:15 PM
CVSS VectorCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
🔗

References & Sources

2
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.
https://www.vmware.com/security/advisories/VMSA-2021-0002.htmlVendor Advisory
https://www.zerodayinitiative.com/advisories/ZDI-21-250/Third Party AdvisoryVDB Entry
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