LibVNC Client resource consumption

CVSS Meta Temp Score
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CTI Interest Score
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6.3$0-$5k0.00

Summaryinfo

A vulnerability was found in LibVNC. It has been rated as problematic. This issue affects some unknown processing of the component Client. Performing a manipulation results in resource consumption. This vulnerability is identified as CVE-2018-20021. The attack can be initiated remotely. There is not any exploit available. It is suggested to install a patch to address this issue.

Detailsinfo

A vulnerability was found in LibVNC (version unknown). It has been classified as problematic. This affects an unknown function of the component Client. The manipulation with an unknown input leads to a resource consumption vulnerability. CWE is classifying the issue as CWE-400. The product does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources. This is going to have an impact on availability. The summary by CVE is:

LibVNC before commit c3115350eb8bb635d0fdb4dbbb0d0541f38ed19c contains a CWE-835: Infinite loop vulnerability in VNC client code. Vulnerability allows attacker to consume excessive amount of resources like CPU and RAM

The bug was discovered 12/19/2018. The weakness was released 12/19/2018 by Solar Designer (Website). The advisory is shared at ics-cert.kaspersky.com. This vulnerability is uniquely identified as CVE-2018-20021 since 12/10/2018. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Neither technical details nor an exploit are publicly available. MITRE ATT&CK project uses the attack technique T1499 for this issue.

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 c3115350eb8bb635d0fdb4dbbb0d0541f38ed19c 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†). Entries connected to this vulnerability are available at VDB-128103, VDB-128104, VDB-128119 and VDB-128120. Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Name

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.4
VulDB Meta Temp Score: 6.3

VulDB Base Score: 5.3
VulDB Temp Score: 5.1
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 7.5
NVD Vector: 🔍

CVSSv2info

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

NVD Base Score: 🔍

Exploitinginfo

Class: Resource consumption
CWE: CWE-400 / CWE-404
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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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: c3115350eb8bb635d0fdb4dbbb0d0541f38ed19c

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 🔍
06/19/2023 +1600 days 🔍

Sourcesinfo

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

CVE: CVE-2018-20021 (🔍)
GCVE (CVE): GCVE-0-2018-20021
GCVE (VulDB): GCVE-100-128121
SecurityFocus: 106825 - LibVNCServer Incomplete Fix Multiple Heap Buffer Overflow Vulnerabilities

See also: 🔍

Entryinfo

Created: 12/20/2018 07:49
Updated: 06/19/2023 21:07
Changes: 12/20/2018 07:49 (72), 04/22/2020 08:32 (5), 06/19/2023 21:07 (4)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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