CVE-2017-18922 Memory corruption in n/a

Critical 9.8 Published 30 Jun 2020 Updated 5 Aug 2024

A heap-based buffer overflow in LibVNCServer allows remote attackers to execute arbitrary code or cause denial of service via crafted WebSocket frames.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: Available

What is CVE-2017-18922?

CVE-2017-18922 is a critical memory corruption vulnerability in Canonical Ubuntu Linux, published on 30 Jun 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

It was discovered that websockets.c in LibVNCServer prior to 0.9.12 did not properly decode certain WebSocket frames. A malicious attacker could exploit this by sending specially crafted WebSocket frames to a server, causing a heap-based buffer overflow.

Weakness: CWE-787

Which versions are affected by CVE-2017-18922?

It affects 10 products.

Linux distribution packages (33)

`libvncserver-devel` AlmaLinux:8	All versions	`0.9.11-15.el8_2.1`
`libvncserver` Red Hat:enterprise_linux:7::client	All versions	`0:0.9.9-14.el7_8.1`
`libvncserver-debuginfo` Red Hat:enterprise_linux:7::client	All versions	`0:0.9.9-14.el7_8.1`
`libvncserver-devel` Red Hat:enterprise_linux:7::client	All versions	`0:0.9.9-14.el7_8.1`
`libvncserver` Red Hat:enterprise_linux:7::server	All versions	`0:0.9.9-14.el7_8.1`
`libvncserver-debuginfo` Red Hat:enterprise_linux:7::server	All versions	`0:0.9.9-14.el7_8.1`
`libvncserver-devel` Red Hat:enterprise_linux:7::server	All versions	`0:0.9.9-14.el7_8.1`
`libvncserver` Red Hat:enterprise_linux:7::workstation	All versions	`0:0.9.9-14.el7_8.1`
`libvncserver-debuginfo` Red Hat:enterprise_linux:7::workstation	All versions	`0:0.9.9-14.el7_8.1`
`libvncserver-devel` Red Hat:enterprise_linux:7::workstation	All versions	`0:0.9.9-14.el7_8.1`
`libvncserver` Red Hat:enterprise_linux:8::appstream	All versions	`0:0.9.11-15.el8_2.1`
`libvncserver-debuginfo` Red Hat:enterprise_linux:8::appstream	All versions	`0:0.9.11-15.el8_2.1`
`libvncserver-debugsource` Red Hat:enterprise_linux:8::appstream	All versions	`0:0.9.11-15.el8_2.1`
`libvncserver` Red Hat:enterprise_linux:8::crb	All versions	`0:0.9.11-15.el8_2.1`
`libvncserver-debuginfo` Red Hat:enterprise_linux:8::crb	All versions	`0:0.9.11-15.el8_2.1`
`libvncserver-debugsource` Red Hat:enterprise_linux:8::crb	All versions	`0:0.9.11-15.el8_2.1`
`libvncserver-devel` Red Hat:enterprise_linux:8::crb	All versions	`0:0.9.11-15.el8_2.1`
`libvncserver` Red Hat:rhel_e4s:8.0::appstream	All versions	`0:0.9.11-9.el8_0.3`
`libvncserver-debuginfo` Red Hat:rhel_e4s:8.0::appstream	All versions	`0:0.9.11-9.el8_0.3`
`libvncserver-debugsource` Red Hat:rhel_e4s:8.0::appstream	All versions	`0:0.9.11-9.el8_0.3`
`libvncserver` Red Hat:rhel_eus:8.1::appstream	All versions	`0:0.9.11-9.el8_1.3`
`libvncserver-debuginfo` Red Hat:rhel_eus:8.1::appstream	All versions	`0:0.9.11-9.el8_1.3`
`libvncserver-debugsource` Red Hat:rhel_eus:8.1::appstream	All versions	`0:0.9.11-9.el8_1.3`
`libvncserver` Red Hat:rhel_eus:8.1::crb	All versions	`0:0.9.11-9.el8_1.3`
`libvncserver-debuginfo` Red Hat:rhel_eus:8.1::crb	All versions	`0:0.9.11-9.el8_1.3`
`libvncserver-debugsource` Red Hat:rhel_eus:8.1::crb	All versions	`0:0.9.11-9.el8_1.3`
`libvncserver-devel` Red Hat:rhel_eus:8.1::crb	All versions	`0:0.9.11-9.el8_1.3`
`LibVNCServer` SUSE:Linux Enterprise Module for Package Hub 15 SP1	All versions	`0.9.10-4.19.1`
`LibVNCServer` SUSE:Linux Enterprise Module for Package Hub 15 SP2	All versions	`0.9.10-4.19.1`
`LibVNCServer` SUSE:Linux Enterprise Workstation Extension 15 SP1	All versions	`0.9.10-4.19.1`
`LibVNCServer` SUSE:Linux Enterprise Workstation Extension 15 SP2	All versions	`0.9.10-4.19.1`
`LibVNCServer` openSUSE:Leap 15.1	All versions	`0.9.10-lp151.7.6.1`
`LibVNCServer` openSUSE:Leap 15.2	All versions	`0.9.10-lp152.9.4.1`

Products include Canonical Ubuntu Linux, Fedoraproject Fedora, Libvncserver Project Libvncserver, Opensuse Leap, Siemens Simatic Itc1500 Firmware, Siemens Simatic Itc1500 Pro Firmware and 4 more.

How do I fix CVE-2017-18922?

Upgrade to a fixed version.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2017-18922 being exploited?

There is no known exploitation of CVE-2017-18922 in the wild and no public exploit code.

All Canonical Ubuntu Linux vulnerabilities

Sources

Also known as ALSA-2020:3385, DEBIAN-CVE-2017-18922, GHSA-hq8f-cpqj-qph2, RHSA-2020:3281, RHSA-2020:3385, RHSA-2020:3456 and 5 more.