CVE-2020-37134

Exploitation

Public exploit code exists. CISA's assessment records a public proof of concept. That is not a report of exploitation in the wild.

SSVC decision

• ExploitationpocPublic proof-of-concept exploit code exists. Not a report of exploitation in the wild.
• AutomatableyesAn attacker can reliably automate reconnaissance through exploitation, so this scales.
• Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

0.41% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 34.9% of scored records. A rank, not a probability.

NVD base score

4.6 (CVSS v4.0), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

NVD analysis status

Deferred. NVD last modified this record on 2026-06-17.

Red Hat severity

No Red Hat rating. Red Hat rates the CVEs that affect its products.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2026-02-05 16:13Z8 MO AGO

Last updated

2026-03-05 01:28Z7 MO AGO

Reserved

2026-02-03

Assigning CNA

VulnCheck

Record state

PUBLISHED

Severity

Medium (CVSS 4.6)

CNA CVSS vector

CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

Weaknesses

• CWE-770Allocation of Resources Without Limits or ThrottlingBase

Data version

5.2

Document digest

ad706d633ee443028d9fab6134a35316f34eb3bd316cdf4647a6850ceff2aa5e

• www.exploit-db.comExploitDB-48291https://www.exploit-db.com/exploits/48291exploit
• www.uvnc.comUltraVNC Official Homepagehttps://www.uvnc.com/product
• www.vulncheck.comVulnCheck Advisory: UltraVNC Viewer 1.2.4.0 - 'VNCServer' Denial of Servicehttps://www.vulncheck.com/advisories/ultravnc-viewer-vncserver-denial-of-servicethird-party-advisory