VDB-188398 · CVE-2021-39656 · A-174049066

Google Android Kernel file.c __configfs_open_file use after free

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.
4.0	$0-$5k	0.00

Summaryinfo

A vulnerability classified as critical was found in Google Android. Affected by this issue is the function __configfs_open_file of the file file.c of the component Kernel. Executing a manipulation can lead to use after free. This vulnerability appears as CVE-2021-39656. The attack requires local access. There is no available exploit. It is best practice to apply a patch to resolve this issue.

Detailsinfo

A vulnerability classified as critical was found in Google Android (Smartphone Operating System) (version unknown). This vulnerability affects the function __configfs_open_file of the file file.c of the component Kernel. The manipulation with an unknown input leads to a use after free vulnerability. The CWE definition for the vulnerability is CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. As an impact it is known to affect confidentiality, integrity, and availability.

The weakness was presented 12/16/2021 as A-174049066. The advisory is available at source.android.com. This vulnerability was named CVE-2021-39656 since 08/23/2021. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 12/16/2021). It is expected to see the exploit prices for this product increasing in the near future.

Applying a patch is able to eliminate this problem.

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Productinfo

Type

Smartphone Operating System

Vendor

Google

Name

Android

License

free

Website

Vendor: https://www.google.com/

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 4.2
VulDB Meta Temp Score: 4.0

VulDB Base Score: 4.2
VulDB Temp Score: 4.0
VulDB Vector: 🔍
VulDB Reliability: 🔍

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: Use after free
CWE: CWE-416 / CWE-119
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: No

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: 🔍

Timelineinfo

08/23/2021 🔍
12/16/2021 +115 days 🔍
12/16/2021 +0 days 🔍
12/18/2021 +2 days 🔍

Sourcesinfo

Vendor: google.com

Advisory: A-174049066
Status: Confirmed

CVE: CVE-2021-39656 (🔍)
GCVE (CVE): GCVE-0-2021-39656
GCVE (VulDB): GCVE-100-188398
scip Labs: https://www.scip.ch/en/?labs.20150917

Entryinfo

Created: 12/16/2021 08:51
Updated: 12/18/2021 17:02
Changes: 12/16/2021 08:51 (42), 12/18/2021 17:02 (1)
Complete: 🔍
Cache ID: 216::103