Linux Kernel Virtual Function mbochs.c mbochs_ioctl 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.
4.8	$0-$5k	0.00

A vulnerability classified as problematic has been found in Linux Kernel (Operating System) (affected version not known). This affects the function mbochs_ioctl of the file samples/vfio-mdev/mbochs.c of the component Virtual Function Handler. The manipulation with an unknown input leads to a information disclosure vulnerability. CWE is classifying the issue as CWE-200. The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information. This is going to have an impact on confidentiality. The summary by CVE is:

A flaw was found in the Linux kernel. A memory leak problem was found in mbochs_ioctl in samples/vfio-mdev/mbochs.c in Virtual Function I/O (VFIO) Mediated devices. This flaw could allow a local attacker to leak internal kernel information.

The weakness was disclosed 08/24/2022. It is possible to read the advisory at access.redhat.com. This vulnerability is uniquely identified as CVE-2021-3736 since 08/26/2021. Technical details of the vulnerability are known, but there is no available exploit. The attack technique deployed by this issue is T1592 according to MITRE ATT&CK.

Applying the patch de5494af4815a4c9328536c72741229b7de88e7f is able to eliminate this problem. The bugfix is ready for download at github.com.

The entry VDB-76440 is pretty similar.

Productinfo

Type

Operating System

Vendor

Linux

Name

Kernel

License

open-source

CPE 2.3info

🔍

CPE 2.2info

🔍

CVSSv4info

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

CVSSv3info

VulDB Meta Base Score: 4.9
VulDB Meta Temp Score: 4.8

VulDB Base Score: 4.3
VulDB Temp Score: 4.1
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 5.5
NVD Vector: 🔍

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
unlock	unlock	unlock	unlock	unlock	unlock
unlock	unlock	unlock	unlock	unlock	unlock
unlock	unlock	unlock	unlock	unlock	unlock

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

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-Day	unlock	unlock	unlock	unlock
Today	unlock	unlock	unlock	unlock

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Patch
Status: 🔍

0-Day Time: 🔍

Patch: de5494af4815a4c9328536c72741229b7de88e7f

Timelineinfo

08/26/2021 🔍
08/24/2022 +363 days 🔍
08/24/2022 +0 days 🔍
09/25/2022 +32 days 🔍

Sourcesinfo

Vendor: kernel.org

Advisory: de5494af4815a4c9328536c72741229b7de88e7f
Status: Confirmed

CVE: CVE-2021-3736 (🔍)
See also: 🔍

Entryinfo

Created: 08/24/2022 07:50
Updated: 09/25/2022 08:08
Changes: 08/24/2022 07:50 (43), 09/25/2022 08:02 (1), 09/25/2022 08:08 (11)
Complete: 🔍
Cache ID: 3:5C8:103