SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

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 server.

CRITICAL 9.8EPSS 2.27%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (2.27%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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 3.1
9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
2.27% probability · 82th percentile
CISA KEV
Not listed
Weakness
CWE-120
Affected
tightvnc/tightvnc
Source
cve_disclosure@tech.gov.sg

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.