RHEL 8 : libvncserver (RHSA-2021:1811)

high Nessus Plugin ID 149663

Synopsis

The remote Red Hat host is missing one or more security updates for libvncserver.

Description

The remote Redhat Enterprise Linux 8 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2021:1811 advisory.

LibVNCServer is a C library that enables you to implement VNC server functionality into own programs.

Security Fix(es):

* libvncserver: uninitialized memory contents are vulnerable to Information Leak (CVE-2018-21247)

* libvncserver: buffer overflow in ConnectClientToUnixSock() (CVE-2019-20839)

* libvncserver: libvncserver/rfbregion.c has a NULL pointer dereference (CVE-2020-14397)

* libvncserver: libvncclient/rfbproto.c does not limit TextChat size (CVE-2020-14405)

* libvncserver: libvncserver/rfbserver.c has a divide by zero which could result in DoS (CVE-2020-25708)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Additional Changes:

For detailed information on changes in this release, see the Red Hat Enterprise Linux 8.4 Release Notes linked from the References section.

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Solution

Update the RHEL libvncserver package based on the guidance in RHSA-2021:1811.

See Also

http://www.nessus.org/u?5b2d223f

http://www.nessus.org/u?862005a9

https://access.redhat.com/security/updates/classification/#moderate

https://access.redhat.com/errata/RHSA-2021:1811

https://bugzilla.redhat.com/show_bug.cgi?id=1849877

https://bugzilla.redhat.com/show_bug.cgi?id=1849886

https://bugzilla.redhat.com/show_bug.cgi?id=1860325

https://bugzilla.redhat.com/show_bug.cgi?id=1860344

https://bugzilla.redhat.com/show_bug.cgi?id=1896739

Plugin Details

Severity: High

ID: 149663

File Name: redhat-RHSA-2021-1811.nasl

Version: 1.12

Type: local

Agent: unix

Published: 5/19/2021

Updated: 11/7/2024

Supported Sensors: Agentless Assessment, Frictionless Assessment Agent, Frictionless Assessment AWS, Frictionless Assessment Azure, Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 4.4

Vendor

Vendor Severity: Moderate

CVSS v2

Risk Factor: Medium

Base Score: 5

Temporal Score: 3.9

Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:N/A:N

CVSS Score Source: CVE-2018-21247

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.7

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Temporal Vector: CVSS:3.0/E:P/RL:O/RC:C

Vulnerability Information

CPE: p-cpe:/a:redhat:enterprise_linux:libvncserver-devel, p-cpe:/a:redhat:enterprise_linux:libvncserver, cpe:/o:redhat:enterprise_linux:8

Required KB Items: Host/local_checks_enabled, Host/RedHat/release, Host/RedHat/rpm-list, Host/cpu

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 5/18/2021

Vulnerability Publication Date: 6/17/2020

Reference Information

CVE: CVE-2018-21247, CVE-2019-20839, CVE-2020-14397, CVE-2020-14405, CVE-2020-25708

CWE: 119, 120, 200, 369, 770

RHSA: 2021:1811