Skip to main content

Horizon Client CVE-2020-3989

LOW
Out-of-bounds Write (CWE-787)
2020-09-16 security@vmware.com
3.3
CVSS 3.1 · NVD
View

Vulnerability Assessment

Weakness
CWE
ASVS 5.0
V15 - Secure Coding and Architecture Bounds checking, write limits
MITRE ATT&CK

2 techniques across 2 tactics: Execution, Privilege Escalation

The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up.

Impact

CVSS score of 3.3 (LOW). Attack characteristics: local attack vector, low complexity, low privileges required, no user interaction not required.

Exploit ScenarioDerived

A local attacker with access to the system could write data beyond allocated buffer boundaries leading to code execution or crashes.

Monitor Track and reassess. Why: LOW severity (CVSS 0.1-3.9).
No patch listed yet 0.3% exploitation probability (EPSS)

Get an e-mail when this CVE is exploited, patched or re-scored. Free account.

Alert me

AnalysisAI

VMware Workstation (15.x) and Horizon Client for Windows (5.x before 5.4.4) contain a denial of service vulnerability due to an out-of-bounds write issue in Cortado ThinPrint component. Rated low severity (CVSS 3.3), this vulnerability is low attack complexity. No vendor patch available.

RemediationAI

No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Validate write boundaries, use memory-safe languages, enable compiler protections (ASLR, stack canaries).

Affects your stack

Find out whether the stacks and servers you run are on an affected version.

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

This vulnerability is classified as Out-of-bounds Write (CWE-787), which allows attackers to write data beyond allocated buffer boundaries leading to code execution or crashes. VMware Workstation (15.x) and Horizon Client for Windows (5.x before 5.4.4) contain a denial of service vulnerability due to an out-of-bounds write issue in Cortado ThinPrint component. A malicious actor with normal access to a virtual machine may be able to exploit this issue to create a partial denial-of-service condition on the system where Workstation or Horizon Client for Windows is installed. Exploitation is only possible if virtual printing has been enabled. This feature is not enabled by default on Workstation but it is enabled by default on Horizon Client. Affected products include: Vmware Horizon Client, Vmware Workstation Player, Vmware Workstation Pro. Version information: before 5.4.4.

Severity by source

NVD PRIMARY 3.3 LOW
AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
Low

DescriptionNVD

VMware Workstation (15.x) and Horizon Client for Windows (5.x before 5.4.4) contain a denial of service vulnerability due to an out-of-bounds write issue in Cortado ThinPrint component. A malicious actor with normal access to a virtual machine may be able to exploit this issue to create a partial denial-of-service condition on the system where Workstation or Horizon Client for Windows is installed. Exploitation is only possible if virtual printing has been enabled. This feature is not enabled by default on Workstation but it is enabled by default on Horizon Client.

Threat Intelligence Overview

EPSS Score
0.3%
Top 79% exploitable
Data Quality
2 sources
Confidence: Low

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue
Severity LOW
CISA KEV No
Public POC No
EPSS 0.3%
Patch available No
Active threat No
Deciding rule
LOW severity (CVSS 0.1-3.9)
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived
Defer
Exploitation· derived
None
System Exposure· derived
Small
Automatable· derived
No
Human Impact· derived
Low

Priority Score

16
Low Medium High Critical
KEV: 0
EPSS: 0
CVSS: +16
PoC: 0
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

A buffer overflow occurs when a program writes more data to a memory buffer than it was allocated to hold, causing the excess data to spill into adjacent memory regions.

Memory corruption occurs when a program writes data beyond the boundaries of allocated memory regions or accesses memory in unintended ways, violating the integrity of the process's address space.

Denial of Service attacks render applications or systems unavailable by overwhelming resources or triggering failure conditions.

Affected Products (CPE)NVD

cpe:2.3:a:vmware:horizon_client:*:*:*:*:*:windows:*:*
cpe:2.3:a:vmware:workstation_player:*:*:*:*:*:*:*:*
cpe:2.3:a:vmware:workstation_pro:*:*:*:*:*:*:*:*
CVE-2020-3950 HIGH POC
7.8 Mar 17

VMware Fusion (11.x before 11.5.2), VMware Remote Console for Mac (11.x and prior before 11.0.1) and Horizon Client for

CVE-2020-3974 HIGH
7.8 Jul 10

VMware Fusion (11.x before 11.5.5), VMware Remote Console for Mac (11.x and prior before 11.2.0 ) and Horizon Client for

CVE-2020-3961 HIGH
7.8 Jun 15

VMware Horizon Client for Windows (prior to 5.4.3) contains a privilege escalation vulnerability due to folder permissio

CVE-2018-6964 HIGH
7.8 May 29

VMware Horizon Client for Linux (4.x before 4.8.0 and prior) contains a local privilege escalation vulnerability due to

CVE-2020-3991 HIGH
7.1 Oct 16

VMware Horizon Client for Windows (5.x before 5.5.0) contains a denial-of-service vulnerability due to a file system acc

CVE-2020-3957 HIGH
7.0 May 29

VMware Fusion (11.x before 11.5.5), VMware Remote Console for Mac (11.x and prior) and VMware Horizon Client for Mac (5.

CVE-2021-21989 MEDIUM
6.5 May 24

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

CVE-2021-21988 MEDIUM
6.5 May 24

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

CVE-2021-21987 MEDIUM
6.5 May 24

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

CVE-2020-3998 MEDIUM
6.5 Oct 23

VMware Horizon Client for Windows (5.x prior to 5.5.0) contains an information disclosure vulnerability. Rated medium se

CVE-2020-3990 MEDIUM
6.5 Sep 16

VMware Workstation (15.x) and Horizon Client for Windows (5.x before 5.4.4) contain an information disclosure vulnerabil

CVE-2018-6970 MEDIUM
6.5 Aug 13

VMware Horizon 6 (6.x.x before 6.2.7), Horizon 7 (7.x.x before 7.5.1), and Horizon Client (4.x.x and prior before 4.8.1)

This site uses cookies essential for authentication and security. No tracking or analytics cookies are used. Privacy Policy