Is CVE-2021-21989 in the CISA KEV catalog?

No. CVE-2021-21989 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2021-21989?

CVE-2021-21989 has a CVSS v3 base score of 6.5 (MEDIUM).

What is the EPSS score for CVE-2021-21989?

CVE-2021-21989 has an EPSS score of 0.45% (36th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2021-21989?

Upgrade horizon client to 5.5.2 or later. Fixes are available for 2 affected products.

CVE & CISA-KEV Catalog

CVE-2021-21989

MEDIUM

6.5

CVSS v3

NVD

Description

VMware Workstation (16.x prior to 16.1.2) and Horizon Client for Windows (5.x prior to 5.5.2) contain out-of-bounds read vulnerability in the Cortado ThinPrint component (TTC Parser). A malicious actor with access to a virtual machine or remote desktop may be able to exploit these issues leading to information disclosure from the TPView process running on the system where Workstation or Horizon Client for Windows is installed.

CWE-125Out-of-bounds Read

How to fix

Remediation Available

horizon clientNVD

Affected:>= 5.0.0, < 5.5.2Fixed in:5.5.2CVE-2021-21989derived from NVD

workstationNVD

Affected:>= 16.0.0, < 16.1.2Fixed in:16.1.2CVE-2021-21989derived from NVD

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorLocal

Attack ComplexityLow

Privileges RequiredLow

User InteractionNone

ScopeChanged

Impact

ConfidentialityHigh

IntegrityNone

AvailabilityNone

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N

Exploit Intelligence

0.45%probability of exploitation in 30 days

36thpercentile

Low risk: more likely to be exploited than 36% of all known CVEs.

References

Patch1

vmware.com

Third-Party Advisory1

zerodayinitiative.com

Related Vulnerabilities

Other CWE-125 (Out-of-bounds Read) vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2014-0160	High	7.5	100%	KEV	Fix
CVE-2025-5777	High	7.5	100%	KEV + Ransom	Fix
CVE-2021-4034	High	7.8	95%	KEV	Fix
CVE-2023-21769	High	7.5	92%	-	Fix
CVE-2023-49285	High	8.6	89%	-	Fix
CVE-2020-8794	Critical	9.8	89%	-	Fix

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2024-11-21.