Critical severity · published Nov 23, 2021
CVE-2021-42785
Buffer Overflow vulnerability in tvnviewer.exe of TightVNC Viewer allows a remote attacker to execute arbitrary instructions via a crafted FramebufferUpdate packet from a VNC…
9.8
CVSS
2.3%
EPSS
No
On KEV
Description
Buffer Overflow vulnerability in tvnviewer.exe of TightVNC Viewer allows a remote attacker to execute arbitrary instructions via a crafted FramebufferUpdate packet from a VNC server.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)2.3% · higher than 84% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
TI
Tightvnc · Tightvnc
through 2.8.59 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-42785
CVE.org
https://www.cve.org/CVERecord?id=CVE-2021-42785
Release Notes
https://www.tightvnc.com/whatsnew.php
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