Detections
Analytics

RHEL 6 : tigervnc (Unpatched Vulnerability)

high Nessus Plugin ID 196470

Synopsis

The remote Red Hat 6 host is affected by multiple vulnerabilities that will not be patched.

Description

The remote Redhat Enterprise Linux 6 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.

 - tigervnc: Stack buffer overflow in CMsgReader::readSetCursor (CVE-2019-15695)

 - tigervnc: certificate exceptions stored as authorities (CVE-2020-26117)

 - In TigerVNC 1.7.1 (SSecurityVeNCrypt.cxx SSecurityVeNCrypt::SSecurityVeNCrypt), an unauthenticated client can cause a small memory leak in the server. (CVE-2017-7392)

 - In TigerVNC 1.7.1 (CConnection.cxx CConnection::CConnection), an unauthenticated client can cause a small memory leak in the server. (CVE-2017-7396)

 - TigerVNC version prior to 1.10.1 is vulnerable to stack use-after-return, which occurs due to incorrect usage of stack memory in ZRLEDecoder. If decoding routine would throw an exception, ZRLEDecoder may try to access stack variable, which has been already freed during the process of stack unwinding. Exploitation of this vulnerability could potentially result into remote code execution. This attack appear to be exploitable via network connectivity. (CVE-2019-15691)

 - TigerVNC version prior to 1.10.1 is vulnerable to heap buffer overflow. Vulnerability could be triggered from CopyRectDecoder due to incorrect value checks. Exploitation of this vulnerability could potentially result into remote code execution. This attack appear to be exploitable via network connectivity.
 (CVE-2019-15692)

 - TigerVNC version prior to 1.10.1 is vulnerable to heap buffer overflow, which occurs in TightDecoder::FilterGradient. Exploitation of this vulnerability could potentially result into remote code execution. This attack appear to be exploitable via network connectivity. (CVE-2019-15693)

 - TigerVNC version prior to 1.10.1 is vulnerable to heap buffer overflow, which could be triggered from DecodeManager::decodeRect. Vulnerability occurs due to the signdness error in processing MemOutStream.
 Exploitation of this vulnerability could potentially result into remote code execution. This attack appear to be exploitable via network connectivity. (CVE-2019-15694)

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: High

ID: 196470

File Name: redhat_unpatched-tigervnc-rhel6.nasl

Version: 1.0

Type: local

Agent: unix

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: Medium

Base Score: 6.5

Temporal Score: 5.1

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

CVSS Score Source: CVE-2019-15695

CVSS v3

Risk Factor: High

Base Score: 8.1

Temporal Score: 7.3

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

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

CVSS Score Source: CVE-2020-26117

Vulnerability Information

CPE: cpe:/o:redhat:enterprise_linux:6, p-cpe:/a:redhat:enterprise_linux:tigervnc

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: 3/31/2017

Reference Information

CVE: CVE-2017-7392, CVE-2017-7396, CVE-2019-15691, CVE-2019-15692, CVE-2019-15693, CVE-2019-15694, CVE-2019-15695, CVE-2020-26117