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AlmaLinux 8 : libvncserver (ALSA-2021:1811)

high Nessus Plugin ID 157648

Synopsis

The remote AlmaLinux host is missing one or more security updates.

Description

The remote AlmaLinux 8 host has packages installed that are affected by multiple vulnerabilities as referenced in the ALSA-2021:1811 advisory.

 - An issue was discovered in LibVNCServer before 0.9.13. There is an information leak (of uninitialized memory contents) in the libvncclient/rfbproto.c ConnectToRFBRepeater function. (CVE-2018-21247)

 - libvncclient/sockets.c in LibVNCServer before 0.9.13 has a buffer overflow via a long socket filename.
 (CVE-2019-20839)

 - An issue was discovered in LibVNCServer before 0.9.13. libvncserver/rfbregion.c has a NULL pointer dereference. (CVE-2020-14397)

 - An issue was discovered in LibVNCServer before 0.9.13. libvncclient/rfbproto.c does not limit TextChat size. (CVE-2020-14405)

 - A divide by zero issue was found to occur in libvncserver-0.9.12. A malicious client could use this flaw to send a specially crafted message that, when processed by the VNC server, would lead to a floating point exception, resulting in a denial of service. (CVE-2020-25708)

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

Solution

Update the affected libvncserver and / or libvncserver-devel packages.

See Also

https://errata.almalinux.org/8/ALSA-2021-1811.html

Plugin Details

Severity: High

ID: 157648

File Name: alma_linux_ALSA-2021-1811.nasl

Version: 1.4

Type: local

Published: 2/9/2022

Updated: 11/10/2023

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 4.4

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:alma:linux:libvncserver, p-cpe:/a:alma:linux:libvncserver-devel, cpe:/o:alma:linux:8

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

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