CVE-2021-22017 (GCVE-0-2021-22017)
Vulnerability from cvelistv5 – Published: 2021-09-23 12:13 – Updated: 2025-10-21 23:25Summary
Rhttproxy as used in vCenter Server contains a vulnerability due to improper implementation of URI normalization. A malicious actor with network access to port 443 on vCenter Server may exploit this issue to bypass proxy leading to internal endpoints being accessed.
Severity
5.3 (Medium)
SSVC
Exploitation: active
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2025-01-29 17:54 UTC
CWE
- Rhttpproxy bypass vulnerability
- CWE-noinfo Not enough information
Assigner
References
2 references
| URL | Tags |
|---|---|
| https://www.vmware.com/security/advisories/VMSA-2… | x_refsource_MISC |
| https://www.cisa.gov/known-exploited-vulnerabilit… | government-resource |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| n/a | VMware vCenter Server, VMware Cloud Foundation |
Affected:
VMware vCenter Server(6.7 before 6.7 U3o and 6.5 before 6.5 U3q) and VMware Cloud Foundation 3.x before 3.10.2.2
|
CISA
Known Exploited Vulnerability - GCVE BCP-07 Compliant
KEV entry ID: 3a484eea-6281-4a0f-aa0b-7391c4390ef8
Exploited: Yes
Timestamps
First Seen: 2022-01-10
Asserted: 2022-01-10
Scope
Notes: VMware vCenter Server Improper Access Control | Affected: VMware / vCenter Server | Description: Rhttproxy as used in vCenter Server contains a vulnerability due to improper implementation of URI normalization. | Required action: Apply updates per vendor instructions. | Due date: 2022-01-24 | Known ransomware campaign use (KEV): Unknown | Notes (KEV): https://nvd.nist.gov/vuln/detail/CVE-2021-22017
Evidence
Type: Vendor Report
Signal: Successful Exploitation
Confidence: 80%
Source: cisa-kev
Details
| Cwes | CWE-23 |
|---|---|
| Feed | CISA Known Exploited Vulnerabilities Catalog |
| Product | vCenter Server |
| Due Date | 2022-01-24 |
| Date Added | 2022-01-10 |
| Vendorproject | VMware |
| Vulnerabilityname | VMware vCenter Server Improper Access Control |
| Knownransomwarecampaignuse | Unknown |
References
Created: 2026-10-02 08:10 CEST
| Updated: 2026-10-02 08:10 CEST
Previdian
Known Exploited Vulnerability - GCVE BCP-07 Compliant
KEV entry ID: 72eefba3-38a3-4580-acdf-309dd3a84e88
Exploited: Yes
Timestamps
First Seen: 2022-01-10
Asserted: 2022-01-10
Scope
Notes: Rhttproxy as used in vCenter Server contains a vulnerability due to improper implementation of URI normalization. A malicious actor with network... | Affected: VMware / VMware vCenter Server, VMware Cloud Foundation | CVSS: 5.3 (MEDIUM) | EPSS: 0.49177 | Used in malware: unknown | Not yet in CISA KEV: False
Evidence
Type: Public Report
Signal: Successful Exploitation
Confidence: 70%
Source: previdian
Details
| Feed | Previdian (previdian.com) |
|---|---|
| Title | Rhttproxy as used in vCenter Server contains a vulnerability due to improper implementation of URI normalization. A malicious actor with network... |
| Cve Id | CVE-2021-22017 |
| Vendor | VMware |
| Ghsa Id | None |
| Product | VMware vCenter Server, VMware Cloud Foundation |
| Added Date | 2022-01-10T00:00:00.000Z |
| Cvss Score | 5.3 |
| Epss Score | 0.49177 |
| Previous Ids | |
| Cvss Severity | MEDIUM |
| Virtual Patch | False |
| Cvss Estimated | False |
| Epss Percentile | 0.98851 |
| Used In Malware | unknown |
| Vulnerability Id | CVE-2021-22017 |
| Ahead Of Cisa Kev | None |
| Not Yet In Cisa Kev | False |
References
Created: 2026-10-02 09:10 CEST
| Updated: 2026-10-02 09:10 CEST
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
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Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.
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