CVE-2021-20590
CWE-287Published: April 22, 2021· Updated: Jun 17, 2026
Official Description
Improper authentication vulnerability in GOT2000 series GT27 model VNC server versions 01.39.010 and prior, GOT2000 series GT25 model VNC server versions 01.39.010 and prior, GOT2000 series GT21 model GT2107-WTBD VNC server versions 01.40.000 and prior, GOT2000 series GT21 model GT2107-WTSD VNC server versions 01.40.000 and prior, GOT SIMPLE series GS21 model GS2110-WTBD-N VNC server versions 01.40.000 and prior and GOT SIMPLE series GS21 model GS2107-WTBD-N VNC server versions 01.40.000 and prior allows a remote unauthenticated attacker to gain unauthorized access via specially crafted packets when the "VNC server" function is used.
Technical Analysis
CVE-2021-20590 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.
The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.
A successful exploit results in full integrity compromise (data manipulation), with a CVSS base score of 7.5.
From a weakness classification perspective (CWE-287): Authentication bypass vulnerabilities allow attackers to access protected resources without valid credentials.
CVSS v3.1 Vector Breakdown
Affected Vendors & Products
Exploit & PoC Resources
All References (4)
Quick Facts
Related CVEs (CWE-287)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2021-20590 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts