LibVNC Client information disclosure

CVSS Meta Temp Score
CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.
Current Exploit Price (≈)
Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.
CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
7.7$0-$5k0.00

A vulnerability was found in LibVNC (affected version not known). It has been rated as critical. This issue affects some unknown functionality of the component Client. The manipulation with an unknown input leads to a information disclosure vulnerability. Using CWE to declare the problem leads to CWE-200. The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

LibVNC before 8b06f835e259652b0ff026898014fc7297ade858 contains CWE-665: Improper Initialization vulnerability in VNC Repeater 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

The bug was discovered 12/19/2018. The weakness was presented 12/19/2018 by Solar Designer (Website). It is possible to read the advisory at ics-cert.kaspersky.com. The identification of this vulnerability is CVE-2018-20023 since 12/10/2018. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. The technical details are unknown and an exploit is not publicly available. The attack technique deployed by this issue is T1592 according to MITRE ATT&CK.

The vulnerability scanner Nessus provides a plugin with the ID 119877 (Debian DLA-1617-1 : libvncserver security update), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Debian Local Security Checks and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 171837 (SUSE Enterprise Linux Security Update for LibVNCServer (SUSE-SU-2019:0060-1)).

Applying the patch 8b06f835e259652b0ff026898014fc7297ade858 is able to eliminate this problem. A possible mitigation has been published 1 weeks after the disclosure of the vulnerability.

The vulnerability is also documented in the databases at Tenable (119877) and SecurityFocus (BID 106825†).

Productinfo

Name

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB CVSS-B Score: 🔍
VulDB CVSS-BT Score: 🔍
VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.9
VulDB Meta Temp Score: 7.7

VulDB Base Score: 8.3
VulDB Temp Score: 7.9
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 7.5
NVD Vector: 🔍

CVSSv2info

AVACAuCIA
💳💳💳💳💳💳
💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
unlockunlockunlockunlockunlockunlock
unlockunlockunlockunlockunlockunlock
unlockunlockunlockunlockunlockunlock

VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Information disclosure
CWE: CWE-200 / CWE-284 / CWE-266
CAPEC: 🔍
ATT&CK: 🔍

Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-Dayunlockunlockunlockunlock
Todayunlockunlockunlockunlock

Nessus ID: 119877
Nessus Name: Debian DLA-1617-1 : libvncserver security update
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Patch
Status: 🔍

Reaction Time: 🔍
0-Day Time: 🔍
Exposure Time: 🔍

Patch: 8b06f835e259652b0ff026898014fc7297ade858

Timelineinfo

12/10/2018 🔍
12/19/2018 +9 days 🔍
12/19/2018 +0 days 🔍
12/19/2018 +0 days 🔍
12/20/2018 +1 days 🔍
12/26/2018 +6 days 🔍
12/27/2018 +1 days 🔍
01/31/2019 +35 days 🔍
06/20/2023 +1601 days 🔍

Sourcesinfo

Advisory: USN-3877-1
Researcher: Solar Designer
Status: Confirmed

CVE: CVE-2018-20023 (🔍)
SecurityFocus: 106825 - LibVNCServer Incomplete Fix Multiple Heap Buffer Overflow Vulnerabilities

Entryinfo

Created: 12/20/2018 07:50 AM
Updated: 06/20/2023 06:42 AM
Changes: 12/20/2018 07:50 AM (73), 04/22/2020 08:58 AM (5), 06/20/2023 06:42 AM (4)
Complete: 🔍
Cache ID: 18:599:40

Discussion

No comments yet. Languages: en.

Please log in to comment.

◂ PreviousOverviewNext ▸

Do you know our Splunk app?

Download it now for free!