Cyber Resilience

CVE-2021-21975

SSRF in Vmware Cloud Foundation 3.0 … 4.0.1

CISA KEVActive ExploitationEUVD ExploitedPublic PoCRansomware-linkedSSRF
Published
31 March 2021
Modified
12 August 2026
KEV Added
18 January 2022
Patch / advisory
CVSS Score v3.1 7.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS Score 0.78 99.5th percentile
Risk Priority 84 floored blend · peak EPSS

Summary

CVE-2021-21975 is a high-severity SSRF (CWE-918) vulnerability in Vmware Cloud Foundation. Its CVSS base score is 7.5 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 0.5% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog; a public proof-of-concept is referenced.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2021-21975 is a Server Side Request Forgery vulnerability in the vRealize Operations Manager API affecting versions prior to 8.4. The flaw is tracked under CWE-918 and carries a CVSS 3.1 base score of 7.5, reflecting network attack vector, low complexity, and no required privileges or user interaction.

A malicious actor with network access to the vRealize Operations Manager API can exploit the issue to conduct an SSRF attack that results in theft of administrative credentials.

The primary vendor advisory is VMware VMSA-2021-0004, which addresses the affected product versions. The vulnerability is also catalogued in the CISA Known Exploited Vulnerabilities list, confirming observed real-world exploitation activity.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

Server Side Request Forgery in vRealize Operations Manager API (CVE-2021-21975) prior to 8.4 may allow a malicious actor with network access to the vRealize Operations Manager API can perform a Server Side Request Forgery attack to steal administrative credentials.

CWE(s)
KEV Date Added
18 January 2022

Related Threats

MITRE ATT&CK Enterprise Techniques

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2021-21973Same product: Vmware Cloud Foundationboth on KEV
CVE-2021-22054Same vendor: Vmwareboth on KEV
CVE-2021-22005Same product: Vmware Cloud Foundationboth on KEV
CVE-2021-21972Same product: Vmware Cloud Foundationboth on KEV
CVE-2021-21985Same product: Vmware Cloud Foundationboth on KEV
CVE-2026-41854Same vendor: Vmware
CVE-2020-3992Same product: Vmware Cloud Foundationboth on KEV
CVE-2024-38813Same product: Vmware Cloud Foundationboth on KEV
CVE-2024-37079Same product: Vmware Cloud Foundationboth on KEV
CVE-2024-38812Same product: Vmware Cloud Foundationboth on KEV

Affected Assets

vmware
cloud foundation
3.0, 3.0.1, 3.0.1.1, 3.10, 3.5
vmware
vrealize operations manager
7.0.0, 7.5.0, 8.0.0, 8.0.1, 8.1.0
vmware
vrealize suite lifecycle manager
8.0, 8.0.1, 8.1, 8.2

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V1.3.6
  • V1.5.3
  • V5.3.2
  • V10.4.7

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-918

Penetration testing attempts server-side requests to internal resources, identifying SSRF weaknesses for remediation.

addresses: CWE-918

Outbound connections to external resources can be monitored and limited at the boundary, reducing SSRF impact.

addresses: CWE-918

Validates server-side URLs and resource references to block SSRF attempts.

addresses: CWE-918

Detects server-side request forgery through monitoring of unexpected outbound connections.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure development practices directly include input validation and destination allow-listing that prevent SSRF.

DE.CM-09 partial match
prevents

Runtime monitoring of web applications and services can detect anomalous outbound requests indicative of SSRF.

ID.RA-01 partial match
prevents

Vulnerability identification processes can discover and record SSRF flaws in web applications.

PR.IR-01 partial match
prevents

Network segmentation and egress controls can limit the damage from successful SSRF requests.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

prevents

Operational threat data describing SSRF campaigns can be used to tighten outbound-request allow-lists and detection rules before attackers exploit them.

References