CVE-2021-21978
Published: April 11, 2026
Official 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.
Risk Analysis
VMware View Planner contains a remote code execution vulnerability due to improper input validation and lack of authorization in its logupload web application. An unauthorized attacker with network access can upload and execute malicious files, leading to remote code execution. This vulnerability is actively exploited, demanding immediate attention.
This vulnerability is actively exploited in the wild and is included in CISA's KEV catalog. Attackers are leveraging this flaw for remote code execution.
VMware View Planner users should upgrade to version 4.6 Security Patch 1 or later. Ensure proper input validation is enforced and restrict network access to the View Planner Harness.
Technical Analysis
CVE-2021-21978 requires local access, meaning attackers must already have a foothold on the target system.
Exploitation requires some privileges, which limits the exposure to scenarios where an attacker has already gained initial access.
CISA has added CVE-2021-21978 to the Known Exploited Vulnerabilities (KEV) catalog, confirming active exploitation in the wild. U.S. federal agencies are required to patch this within the mandated timeframe, and all organizations should treat remediation as urgent.
Affected Vendors & Products
Exploit & PoC Resources
Quick Facts
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2021-21978 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts
- !CISA KEV: Federal agencies must patch per BOD 22-01 timeline
- !Active exploitation confirmed — treat as P1