CVE-2021-21972

VMware vCenter Server: Remote Code Execution

As of , CVE-2021-21972 in VMware vCenter Server is on CISA's list of exploited vulnerabilities: CISA listed it on . Our patch-first group: Patch this week.

Exploited
Yes: CISA listed it on 3 November 2021
US federal deadline
17 November 202114 days after CISA listed it. US federal civilian agencies must fix it by then.
Used in ransomware campaigns
Known
EPSS score
0.99Higher than 99% of the CVEs EPSS scores. EPSS estimates the chance of exploitation activity in the next 30 days.
EPSS when listed
Not availableCISA listed it before 4 February 2022, where the EPSS files we read begin.
Public exploit
1 Metasploit module and 2 Exploit-DB entries
Fix
No vendor link in CISA's entry

What CISA says to do

Apply updates per vendor instructions.

CISA's required action

What the flaw is

VMware vCenter Server vSphere Client contains a remote code execution vulnerability in a vCenter Server plugin which allows an attacker with network access to port 443 to execute commands with unrestricted privileges on the underlying operating system.

CISA's description

The vSphere Client (HTML5) contains a remote code execution vulnerability in a vCenter Server plugin. A malicious actor with network access to port 443 may exploit this issue to execute commands with unrestricted privileges on the underlying operating system that hosts vCenter Server. This affects VMware vCenter Server (7.x before 7.0 U1c, 6.7 before 6.7 U3l and 6.5 before 6.5 U3n) and VMware Cloud Foundation (4.x before 4.2 and 3.x before 3.10.1.2).

The CVE record's description, from vmware

CVE published
24 February 2021
Assigned by
vmware
CVSS
9.8 Critical (CVSS 3.1, from CISA-ADP)
CWE-22
Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
CWE-23
Relative Path Traversal
CISA SSVC, exploitation
active
CISA SSVC, automatable
yes
CISA SSVC, technical impact
total

Timeline

  1. The CVE record was published.
  2. Exploit-DB published an exploit (EDB-ID 49602).
  3. Exploit-DB published an exploit (EDB-ID 50056).
  4. CISA added it to its list of exploited vulnerabilities.
  5. The US federal deadline to fix it.

Public exploits

Facts from Metasploit's module list and Exploit-DB's index; we never copy exploit code.

vCenter Server: other exploited entries

VulnerabilityProductOur groupListedDeadlineEPSS
CVE-2020-3952Information DisclosureVMware vCenter ServerPatch this weekMetasploit module; EPSS 0.900.90
CVE-2021-21985Improper Input ValidationVMware vCenter ServerPatch this weekRansomware use; Metasploit module; EPSS 0.990.99
CVE-2021-22005File UploadVMware vCenter ServerPatch this weekRansomware use; Metasploit module; EPSS 0.990.99
CVE-2022-22948Incorrect Default File PermissionsVMware vCenter ServerPatch this weekMetasploit module0.13
CVE-2023-34048Out-of-Bounds WriteVMware vCenter ServerPatch this weekEPSS 0.990.99
CVE-2024-38812Heap-Based Buffer OverflowVMware vCenter ServerPatch this weekEPSS 0.550.55
CVE-2021-22017Improper Access ControlVMware vCenter ServerPatch soon0.49
CVE-2024-38813Privilege EscalationVMware vCenter ServerPatch soon0.17

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