How severe is CVE-2021-21978?

CVE-2021-21978 has a CVSS score of 9.8/10, rated CRITICAL. Immediate patching is strongly recommended.

Which packages are affected by CVE-2021-21978?

Affected package information for CVE-2021-21978 is not yet fully mapped. Check the official advisory links for details.

How do I fix CVE-2021-21978?

No fixed version has been published for CVE-2021-21978 yet. Monitor the advisory for updates, apply mitigations recommended by the vendor, and use O3 Security to track when a fix becomes available in your stack.

Is CVE-2021-21978 actively exploited in the wild?

Yes. There are 8 known exploit references for CVE-2021-21978, including 5 in-the-wild exploitations observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2021-21978?

CVE-2021-21978 has an EPSS (Exploit Prediction Scoring System) score of 90.5%, placing it in the 100th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. A score above 50% indicates significantly elevated exploitation risk — immediate patching is strongly recommended.

What type of vulnerability is CVE-2021-21978?

CVE-2021-21978 is classified as Improper Input Validation (CWE-20), CWE-862 (CWE-862). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

Which products and versions are affected by CVE-2021-21978?

CVE-2021-21978 affects vmware view planner (1 version, e.g. 4.6). Check the affected-products list on this page against your deployed version to confirm exposure.

Is there exploit tooling available for CVE-2021-21978?

A Nuclei detection template exists for CVE-2021-21978, meaning automated scanners can fingerprint it. Public exploit tooling significantly increases real-world risk — prioritize patching and ensure detection coverage. Exploit tooling should only ever be used in isolated, authorized testing environments.

When was CVE-2021-21978 published, and has it been updated?

CVE-2021-21978 was published on March 3, 2021 and was last updated on November 21, 2024. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CVE-2021-21978

CRITICAL

VMware View Planner 4.x prior to 4.6 Security Patch 1 contains a remote code execution vulnerability. Improper input validation and lack of authorization leading to arbitrary file upload…

Published

Mar 3, 2021

Updated

Nov 21, 2024

Affected

0 pkgs

Patched

None yet

Exploits

8 known

EPSS Exploitation Probability

via FIRST.org ↗

90.5%probability of exploitation in next 30 days

Very High Risk100th percentile0.00%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Description

VMware View Planner 4.x prior to 4.6 Security Patch 1 contains a remote code execution vulnerability. Improper input validation and lack of authorization leading to arbitrary file upload in logupload web application. An unauthorized attacker with network access to View Planner Harness could upload and execute a specially crafted file leading to remote code execution within the logupload container.

Affected Products

1 product · 2 configurations

Application

view plannervmware

≥ 4.0 && < 4.6

1 version

4.6

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.