Description
The rfbProcessClientNormalMessage function in libvncserver/rfbserver.c in LibVNCServer 0.9.9 and earlier does not properly handle attempts to send a large amount of ClientCutText data, which allows remote attackers to cause a denial of service (memory consumption or daemon crash) via a crafted message that is processed by using a single unchecked malloc.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | libvncserver | 0.9.9+dfsg-6.1 | — |
| Debian 14 | tightvnc | 1:1.3.9-9.1 | — |
| Debian 13 | libvncserver | 0.9.9+dfsg-6.1 | — |
| Debian 13 | tightvnc | 1:1.3.9-9.1 | — |
| Debian 12 | libvncserver | 0.9.9+dfsg-6.1 | — |
| Debian 12 | tightvnc | 1:1.3.9-9.1 | — |
| Debian 12 | vino | 3.22.0-6 | — |
| Debian 8 | italc | 1:2.0.2+dfsg1-2+deb8u1 | DLA-1979-1 |
| Debian 8 | tightvnc | 1.3.9-6.5+deb8u1 | DLA-2045-1 |
| Debian 8 | vino | 3.14.0-2+deb8u1 | DLA-2014-1 |
| Debian 7 | libvncserver | 0.9.9+dfsg-1+deb7u1 | DSA-3081-1 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 6.0 | libvncserver | 0.9.7-2+deb6u1 | DLA-197-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | tightvnc | No fix yet | — |
| Ubuntu 26.04 LTS | tightvnc | No fix yet | — |
| Ubuntu 25.10 | tightvnc | No fix yet | — |
| Ubuntu 24.04 LTS | tightvnc | No fix yet | — |
| Ubuntu 22.04 LTS | tightvnc | No fix yet | — |
Show 5 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | tightvnc | No fix yet | — |
| Ubuntu 20.04 LTS | vino | 3.22.0-5ubuntu2.1 | USN-4573-1 |
| Ubuntu 18.04 LTS | tightvnc | No fix yet | — |
| Ubuntu 18.04 LTS | vino | 3.22.0-3ubuntu1.1 | USN-4573-1 |
| Ubuntu 16.04 LTS | italc | 1:2.0.2+dfsg1-4ubuntu0.1 | USN-4587-1 |
| Ubuntu 16.04 LTS | tightvnc | No fix yet | — |
| Ubuntu 16.04 LTS | vino | 3.8.1-0ubuntu9.3 | USN-4573-1 |
| Ubuntu 14.04 LTS | krfb | 4:4.13.3-0ubuntu1.1 | — |
| Ubuntu 14.04 LTS | libvncserver | 0.9.9+dfsg-1ubuntu1.1 | USN-2365-1 |
| Ubuntu Pro 14.04 LTS | tightvnc | 1.3.9-6.5+deb8u1build0.14.04.1~esm1 | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 7 | kdenetwork +14 | 7:4.10.5-8.el7_0 | RHSA-2014:1827 |
| RHEL 7 | libvncserver +1 | 0.9.9-9.el7_0.1 | RHSA-2014:1826 |
| RHEL 6 | libvncserver +1 | 0.9.7-7.el6_6.1 | RHSA-2014:1826 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP1 | LibVNCServer | 0.9.9-16.1 | SUSE-SU-2015:2088-2 |
| SLES 12 | LibVNCServer | 0.9.9-16.1 | SUSE-SU-2015:2088-1 |
| SLES 11 SP4 | LibVNCServer | 0.9.1-156.1 | SUSE-SU-2015:2110-1 |
| SLES 11 SP3 | LibVNCServer | 0.9.1-156.1 | SUSE-SU-2015:2110-1 |
Show 4 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 12 SP1 | LibVNCServer | 0.9.9-16.1 | SUSE-SU-2015:2088-2 |
| SLES for SAP 12 | LibVNCServer | 0.9.9-16.1 | SUSE-SU-2015:2088-1 |
| SLES for SAP 11 SP4 | LibVNCServer | 0.9.1-156.1 | SUSE-SU-2015:2110-1 |
| SLES for SAP 11 SP3 | LibVNCServer | 0.9.1-156.1 | SUSE-SU-2015:2110-1 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 7 | kdenetwork +14 | 7:4.10.5-8.el7_0 | ELSA-2014-1827 |
| Oracle Linux 7 | libvncserver +1 | 0.9.9-9.el7_0.1 | ELSA-2014-1826 |
Advisories 15
- RHSA-2014:1826 Red Hat Security Advisory: libvncserver security update Red Hat Security Advisories (RHSA) · Jun 28, 2026
- RHSA-2014:1827 Red Hat Security Advisory: kdenetwork security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- USN-4587-1 italc vulnerabilities Ubuntu Security Notices (USN) · Apr 27, 2026
- USN-4573-1 vino vulnerabilities Ubuntu Security Notices (USN) · Apr 27, 2026
- USN-2365-1 libvncserver vulnerabilities Ubuntu Security Notices (USN) · Apr 27, 2026
- DLA-2014-1 vino - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-197-1 libvncserver - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-3081-1 libvncserver - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-2045-1 tightvnc - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-1979-1 italc - security update Debian Security (DSA / DLA) · Mar 9, 2026
- SUSE-SU-2015:2088-1 Security update for LibVNCServer SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2015:2088-2 Security update for LibVNCServer SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2015:2110-1 Security update for LibVNCServer SUSE / openSUSE Security Updates · Feb 4, 2026
- ELSA-2014-1827 Moderate: kdenetwork security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Nov 11, 2014
- ELSA-2014-1826 Moderate: libvncserver security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Nov 11, 2014
References
- http://www.ocert.org/advisories/ocert-2014-007.html
- https://github.com/newsoft/libvncserver/commit/6037a9074d52b1963c97cb28ea1096c7c14cbf28
- 61682 third-party-advisory
- openSUSE-SU-2015:2207 vendor-advisory
- 61506 third-party-advisory
- [oss-security] 20140925 [oCERT-2014-007] libvncserver multiple issues mailing-list
- [oss-security] 20140923 Multiple issues in libVNCserver mailing-list
- USN-2365-1 vendor-advisory
- GLSA-201507-07 vendor-advisory
- DSA-3081 vendor-advisory
- [debian-lts-announce] 20191030 [SECURITY] [DLA 1979-1] italc security update mailing-list
- [debian-lts-announce] 20191129 [SECURITY] [DLA 2014-1] vino security update mailing-list
- [debian-lts-announce] 20191221 [SECURITY] [DLA 2045-1] tightvnc security update mailing-list
- USN-4573-1 vendor-advisory
- USN-4587-1 vendor-advisory