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Fencer Vulns
critical 10.0

CVE-2008-4770 json

The CMsgReader::readRect function in the VNC Viewer component in RealVNC VNC Free Edition 4.0 through 4.1.2, Enterprise Edition E4.0 throug…

published 2009-01-16 17 y ago modified 2026-06-16 4 mo ago also EUVD-2008-4750

cvss
10.0
version 2.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
4.1%
EPSS 4.1% chance of exploitation in 30 days, percentile 90%
public exploits
0
none known

Summary

The CMsgReader::readRect function in the VNC Viewer component in RealVNC VNC Free Edition 4.0 through 4.1.2, Enterprise Edition E4.0 through E4.4.2, and Personal Edition P4.0 through P4.4.2 allows remote VNC servers to execute arbitrary code via crafted RFB protocol data, related to "encoding type."

Patch / fix

  • vnc RHEL 3 4.0-0.beta4.1.8
  • vnc RHEL 4 4.0-12.el4_7.1
  • vnc RHEL 5 4.1.2-14.el5_3.1
  • vnc-server RHEL 3 4.0-0.beta4.1.8
  • vnc-server RHEL 4 4.0-12.el4_7.1
  • vnc-server RHEL 5 4.1.2-14.el5_3.1

red hat advisories RHSA-2009:0261

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2008-4770 updated

vnc: vncviewer insufficient encoding value validation in CMsgReader::readRect

  • Red Hat Desktop version 3 vnc 4.0-0.beta4.1.8, vnc-server 4.0-0.beta4.1.8 Red Hat Enterprise Linux (v. 5 server) vnc 4.1.2-14.el5_3.1, vnc-server 4.1.2-14.el5_3.1 Red Hat Enterprise Linux AS version 3 vnc 4.0-0.beta4.1.8, vnc-server 4.0-0.beta4.1.8 Red Hat Enterprise Linux AS version 4 vnc 4.0-12.el4_7.1, vnc-server 4.0-12.el4_7.1 Red Hat Enterprise Linux Desktop (v. 5 client) vnc 4.1.2-14.el5_3.1, vnc-server 4.1.2-14.el5_3.1 Red Hat Enterprise Linux Desktop version 4 vnc 4.0-12.el4_7.1, vnc-server 4.0-12.el4_7.1
    +4 more products
    Red Hat Enterprise Linux ES version 3 vnc 4.0-0.beta4.1.8, vnc-server 4.0-0.beta4.1.8 Red Hat Enterprise Linux ES version 4 vnc 4.0-12.el4_7.1, vnc-server 4.0-12.el4_7.1 Red Hat Enterprise Linux WS version 3 vnc 4.0-0.beta4.1.8, vnc-server 4.0-0.beta4.1.8 Red Hat Enterprise Linux WS version 4 vnc 4.0-12.el4_7.1, vnc-server 4.0-12.el4_7.1
    fixed: vendor fix RHSA-2009:0261

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

4.05% chance of exploitation in the next 30 days, higher than 90% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 2.0 10.0 AV:N/AC:L/Au:N/C:C/I:C/A:C

Classification

Weakness
  • CWE-20 Improper Input Validation

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.