ESXi
CVE-2020-3955
CRITICAL
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A05:2025 - Injection
ASVS 5.0
V1 - Encoding and Sanitization Output encoding, context-aware escaping
MITRE ATT&CK
2 techniques across 2 tactics: Initial Access, Execution The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Impact | CVSS score of 9.3 (CRITICAL). Attack characteristics: network attack vector, low complexity, no privileges required, user interaction required. |
| Exploit ScenarioDerived | A remote attacker could inject malicious scripts into web pages viewed by other users by sending crafted requests to the affected application. No authentication is required to exploit this vulnerability. |
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Alert meAnalysisAI
ESXi 6.5 without patch ESXi650-201912104-SG and ESXi 6.7 without patch ESXi670-202004103-SG do not properly neutralize script-related HTML when viewing virtual machines attributes. Rated critical severity (CVSS 9.3), this vulnerability is remotely exploitable, no authentication required, low attack complexity. This Cross-Site Scripting (XSS) vulnerability could allow attackers to inject malicious scripts into web pages viewed by other users.
RemediationAI
A vendor patch is available. Apply the latest security update as soon as possible. Sanitize all user input, use Content-Security-Policy headers, encode output contextually (HTML, JS, URL). Use frameworks with built-in XSS protection.
Affects your stack
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Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
This vulnerability is classified as Cross-Site Scripting (XSS) (CWE-79), which allows attackers to inject malicious scripts into web pages viewed by other users. ESXi 6.5 without patch ESXi650-201912104-SG and ESXi 6.7 without patch ESXi670-202004103-SG do not properly neutralize script-related HTML when viewing virtual machines attributes. VMware has evaluated the severity of this issue to be in the Important severity range with a maximum CVSSv3 base score of 8.3. Affected products include: Vmware Esxi.
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- Exploit and PoC references, threat intelligence from 22 sources
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Severity by source
AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
DescriptionNVD
ESXi 6.5 without patch ESXi650-201912104-SG and ESXi 6.7 without patch ESXi670-202004103-SG do not properly neutralize script-related HTML when viewing virtual machines attributes. VMware has evaluated the severity of this issue to be in the Important severity range with a maximum CVSSv3 base score of 8.3.
Threat Intelligence Overview
NVD
CVE.org
EPSS
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Cross-Site Scripting occurs when an application accepts untrusted data and sends it to a web browser without proper validation or encoding.
Affected Products (CPE)NVD
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-
VMware ESXi and Workstation contain a TOCTOU race condition leading to out-of-bounds write, allowing local administrator
Systems with microprocessors utilizing speculative execution and branch prediction may allow unauthorized disclosure of
VMware ESXi contains an arbitrary write vulnerability that allows privileged VMX process users to trigger kernel writes,
Untrusted search path vulnerability in the HGFS (aka Shared Folders) feature in VMware Tools 10.0.5 in VMware ESXi 5.0 t
VMware ESXi, Workstation, and Fusion contain an information disclosure vulnerability via HGFS out-of-bounds read, allowi
OpenSLP as used in ESXi and the Horizon DaaS appliances has a heap overwrite issue. Rated critical severity (CVSS 9.8),
In the add_match function in libbb/lineedit.c in BusyBox through 1.27.2, the tab autocomplete feature of the shell, used
VMware ESXi (ESXi 6.5 without patch ESXi650-201707101-SG), Workstation (12.x before 12.5.7) and Fusion (8.x before 8.5.8
The Service Location Protocol (SLP, RFC 2608) allows an unauthenticated, remote attacker to register arbitrary services.
The Virtual Machine Communication Interface (VMCI) implementation in vmci.sys in VMware Workstation 8.x before 8.0.5 and
VMware ESXi (6.5 before ESXi650-201710401-BG), Workstation (12.x before 12.5.8), and Fusion (8.x before 8.5.9) contain a
GitHub PoC
Exploit-DB