VDB-195790 · CVE-2021-4203 · GCVE-0-2021-4203

Linux Kernel up to 5.15-rc3 net/core/sock.c sock_getsockopt 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.
6.8	$0-$5k	0.00

Summaryinfo

A vulnerability classified as critical was found in Linux Kernel up to 5.15-rc3. Affected by this issue is the function sock_getsockopt of the file net/core/sock.c. Executing a manipulation can lead to use after free. This vulnerability is registered as CVE-2021-4203. It is possible to launch the attack remotely. Furthermore, an exploit is available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability has been found in Linux Kernel up to 5.15-rc3 (Operating System) and classified as critical. This vulnerability affects the function sock_getsockopt of the file net/core/sock.c. 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 published 03/26/2022. The advisory is available at bugs.chromium.org. This vulnerability was named CVE-2021-4203 since 01/10/2022. Technical details and also a public exploit are known.

It is possible to download the exploit at bugs.chromium.org. It is declared as proof-of-concept. As 0-day the estimated underground price was around $5k-$25k.

Upgrading to version 5.15-rc3 eliminates this vulnerability. Applying a patch is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

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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: 7.6
VulDB Meta Temp Score: 6.8

VulDB Base Score: 7.6
VulDB Temp Score: 6.8
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: 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

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: Kernel 5.15-rc3
Patch: git.kernel.org

Timelineinfo

01/10/2022 🔍
03/26/2022 +75 days 🔍
03/26/2022 +0 days 🔍
03/27/2022 +1 days 🔍

Sourcesinfo

Vendor: kernel.org

Advisory: bugs.chromium.org
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2021-4203 (🔍)
GCVE (CVE): GCVE-0-2021-4203
GCVE (VulDB): GCVE-100-195790
scip Labs: https://www.scip.ch/en/?labs.20161013

Entryinfo

Created: 03/26/2022 07:28
Updated: 03/27/2022 11:37
Changes: 03/26/2022 07:28 (46), 03/27/2022 11:37 (1)
Complete: 🔍
Cache ID: 216::103