VDB-130915 · CVE-2019-6974 · RHSA-2019:0818

Linux Kernel up to 4.20.7 Reference Counting virt/kvm/kvm_main.c kvm_ioctl_create_device race condition

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.
7.5	$0-$5k	0.00

Summaryinfo

A vulnerability, which was classified as critical, has been found in Linux Kernel up to 4.20.7. This issue affects the function kvm_ioctl_create_device of the file virt/kvm/kvm_main.c of the component Reference Counting. This manipulation causes race condition. This vulnerability is registered as CVE-2019-6974. Remote exploitation of the attack is possible. Furthermore, an exploit is available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability classified as critical was found in Linux Kernel up to 4.20.7 (Operating System). Affected by this vulnerability is the function kvm_ioctl_create_device of the file virt/kvm/kvm_main.c of the component Reference Counting. The manipulation with an unknown input leads to a race condition vulnerability. The CWE definition for the vulnerability is CWE-362. The product contains a code sequence that can run concurrently with other code, and the code sequence requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence that is operating concurrently. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel before 4.20.8, kvm_ioctl_create_device in virt/kvm/kvm_main.c mishandles reference counting because of a race condition, leading to a use-after-free.

The bug was discovered 02/15/2019. The weakness was published 02/15/2019 (Website). It is possible to read the advisory at securityfocus.com. This vulnerability is known as CVE-2019-6974 since 01/26/2019. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Technical details and also a public exploit are known.

It is possible to download the exploit at exploit-db.com. It is declared as proof-of-concept. We expect the 0-day to have been worth approximately $5k-$25k. The commercial vulnerability scanner Qualys is able to test this issue with plugin 172088 (SUSE Enterprise Linux Security Update for the Linux Kernel (SUSE-SU-2019:0541-1)).

Upgrading to version 4.20.8 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at SecurityFocus (BID 106253†). Similar entries are available at VDB-113072, VDB-123804, VDB-128011 and VDB-128084. Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Type

Operating System

Vendor

Linux

Name

Kernel

Version

License

open-source

Website

Vendor: https://www.kernel.org/

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.7
VulDB Meta Temp Score: 7.3

VulDB Base Score: 7.3
VulDB Temp Score: 6.6
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 8.1
NVD Vector: 🔍

CVSSv2info

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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Race condition
CWE: CWE-362
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Access: Public
Status: Proof-of-Concept
Download: 🔍

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Qualys ID: 🔍
Qualys Name: 🔍

Exploit-DB: 🔍

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: Kernel 4.20.8
Patch: git.kernel.org

Timelineinfo

12/19/2018 🔍
01/26/2019 +38 days 🔍
02/15/2019 +20 days 🔍
02/15/2019 +0 days 🔍
02/16/2019 +1 days 🔍
12/21/2024 +2135 days 🔍

Sourcesinfo

Vendor: kernel.org

Advisory: RHSA-2019:0818⛔
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2019-6974 (🔍)
GCVE (CVE): GCVE-0-2019-6974
GCVE (VulDB): GCVE-100-130915
SecurityFocus: 106253 - Linux Kernel CVE-2018-16884 Denial of Service Vulnerability

scip Labs: https://www.scip.ch/en/?labs.20161013
See also: 🔍

Entryinfo

Created: 02/16/2019 14:28
Updated: 12/21/2024 21:46
Changes: 02/16/2019 14:28 (64), 05/10/2020 18:30 (5), 07/10/2023 14:59 (6), 12/21/2024 21:46 (22)
Complete: 🔍
Cache ID: 216::103

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.