Linux Kernel up to 4.20.1 kernel/sched/fair.c update_blocked_averages resource consumption

CVSS Meta Temp Score
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CTI Interest Score
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8.4$0-$5k0.00

Summaryinfo

A vulnerability was found in Linux Kernel up to 4.20.1 and classified as critical. This affects the function update_blocked_averages of the file kernel/sched/fair.c. The manipulation results in resource consumption. This vulnerability is known as CVE-2018-20784. It is possible to launch the attack remotely. No exploit is available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 4.20.1 (Operating System). It has been classified as critical. Affected is the function update_blocked_averages of the file kernel/sched/fair.c. 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 confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel before 4.20.2, kernel/sched/fair.c mishandles leaf cfs_rq's, which allows attackers to cause a denial of service (infinite loop in update_blocked_averages) or possibly have unspecified other impact by inducing a high load.

The bug was discovered 12/30/2018. The weakness was published 02/22/2019 (Website). The advisory is shared for download at access.redhat.com. This vulnerability is traded as CVE-2018-20784 since 02/22/2019. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. There are known technical details, but no exploit is available. The MITRE ATT&CK project declares the attack technique as T1499.

The vulnerability was handled as a non-public zero-day exploit for at least 54 days. During that time the estimated underground price was around $5k-$25k.

Upgrading to version 4.20.2 eliminates this vulnerability.

Similar entry is available at VDB-131104. Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.5
VulDB Meta Temp Score: 8.4

VulDB Base Score: 7.3
VulDB Temp Score: 7.0
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 9.8
NVD Vector: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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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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Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: Kernel 4.20.2
Patch: git.kernel.org

Timelineinfo

12/30/2018 🔍
02/22/2019 +54 days 🔍
02/22/2019 +0 days 🔍
02/23/2019 +1 days 🔍
07/19/2023 +1607 days 🔍

Sourcesinfo

Vendor: kernel.org

Advisory: RHSA-2019:1959
Status: Not defined

CVE: CVE-2018-20784 (🔍)
GCVE (CVE): GCVE-0-2018-20784
GCVE (VulDB): GCVE-100-131100
See also: 🔍

Entryinfo

Created: 02/23/2019 07:54
Updated: 07/19/2023 08:41
Changes: 02/23/2019 07:54 (61), 05/12/2020 09:28 (2), 07/19/2023 08:41 (5)
Complete: 🔍
Cache ID: 216::103

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