RHEL 7 : libvncserver (Unpatched Vulnerability)

critical Nessus Plugin ID 196314

Synopsis

The remote Red Hat 7 host is affected by multiple vulnerabilities that will not be patched.

Description

The remote Redhat Enterprise Linux 7 host has one or more packages installed that are affected by multiple vulnerabilities that have been acknowledged by the vendor but will not be patched.

- libvncserver: Multiple heap out-of-bound writes in VNC client code (Incomplete fix for CVE-2018-20019) (CVE-2018-20748)

- Heap-based buffer overflow in rfbproto.c in LibVNCClient in LibVNCServer before 0.9.11 allows remote servers to cause a denial of service (application crash) or possibly execute arbitrary code via a crafted FramebufferUpdate message containing a subrectangle outside of the client drawing area. (CVE-2016-9941)

- Heap-based buffer overflow in ultra.c in LibVNCClient in LibVNCServer before 0.9.11 allows remote servers to cause a denial of service (application crash) or possibly execute arbitrary code via a crafted FramebufferUpdate message with the Ultra type tile, such that the LZO payload decompressed length exceeds what is specified by the tile dimensions. (CVE-2016-9942)

- LibVNC before commit a83439b9fbe0f03c48eb94ed05729cb016f8b72f contains multiple heap out-of-bound write vulnerabilities in VNC client code that can result remote code execution (CVE-2018-20019)

- LibVNC before commit 7b1ef0ffc4815cab9a96c7278394152bdc89dc4d contains heap out-of-bound write vulnerability inside structure in VNC client code that can result remote code execution (CVE-2018-20020)

- LibVNC before 2f5b2ad1c6c99b1ac6482c95844a84d66bb52838 contains multiple weaknesses CWE-665: Improper Initialization vulnerability in VNC client code that allows attacker to read stack memory and can be abuse for information disclosure. Combined with another vulnerability, it can be used to leak stack memory layout and in bypassing ASLR (CVE-2018-20022)

- LibVNC before commit 4a21bbd097ef7c44bb000c3bd0907f96a10e4ce7 contains null pointer dereference in VNC client code that can result DoS. (CVE-2018-20024)

- 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)

- 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)

- libvncclient v0.9.13 was discovered to contain a memory leak via the function rfbClientCleanup().
(CVE-2020-29260)

Note that Nessus has not tested for these issues but has instead relied on the package manager's report that the package is installed.

Solution

The vendor has acknowledged the vulnerabilities but no solution has been provided. Refer to the vendor for remediation guidance.

Plugin Details

Severity: Critical

ID: 196314

File Name: redhat_unpatched-libvncserver-rhel7.nasl

Version: 1.0

Type: local

Agent: unix

Family: Red Hat Local Security Checks

Published: 5/11/2024

Updated: 5/11/2024

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

Risk Information

VPR

Risk Factor: Medium

Score: 6.7

CVSS v2

Risk Factor: High

Base Score: 7.5

Temporal Score: 5.9

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

CVSS Score Source: CVE-2018-20748

CVSS v3

Risk Factor: Critical

Base Score: 9.8

Temporal Score: 8.8

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

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

Vulnerability Information

CPE: cpe:/o:redhat:enterprise_linux:6, cpe:/o:redhat:enterprise_linux:7, cpe:/o:redhat:enterprise_linux:8, p-cpe:/a:redhat:enterprise_linux:libvncserver, p-cpe:/a:redhat:enterprise_linux:vino

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

Exploit Available: true

Exploit Ease: Exploits are available

Vulnerability Publication Date: 12/31/2016

Reference Information

CVE: CVE-2016-9941, CVE-2016-9942, CVE-2018-20019, CVE-2018-20020, CVE-2018-20022, CVE-2018-20024, CVE-2018-20748, CVE-2018-21247, CVE-2019-20839, CVE-2020-25708, CVE-2020-29260

Detections

Analytics