VDB-193340 · CVE-2021-4090 · GCVE-0-2021-4090

Linux Kernel NFSD fs/nfsd/nfs4xdr.c nfsd4_decode_bitmap4 memory corruption

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.
8.4	$0-$5k	0.00

Summaryinfo

A vulnerability classified as critical was found in Linux Kernel. This issue affects the function nfsd4_decode_bitmap4 of the file fs/nfsd/nfs4xdr.c of the component NFSD. Such manipulation leads to memory corruption. This vulnerability is referenced as CVE-2021-4090. It is possible to launch the attack remotely. No exploit is available. It is advisable to implement a patch to correct this issue.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Linux Kernel (Operating System) (version unknown). Affected by this issue is the function nfsd4_decode_bitmap4 of the file fs/nfsd/nfs4xdr.c of the component NFSD. The manipulation with an unknown input leads to a memory corruption vulnerability. Using CWE to declare the problem leads to CWE-119. The product performs operations on a memory buffer, but it can read from or write to a memory location that is outside of the intended boundary of the buffer. Impacted is confidentiality, integrity, and availability.

The weakness was published 02/18/2022. The advisory is shared for download at bugzilla.redhat.com. This vulnerability is handled as CVE-2021-4090 since 12/10/2021. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 02/18/2022).

Applying a patch is able to eliminate this problem. The bugfix is ready for download at lore.kernel.org.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

Operating System

Vendor

Linux

Name

Kernel

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: 8.8
VulDB Meta Temp Score: 8.4

VulDB Base Score: 8.8
VulDB Temp Score: 8.4
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: Memory corruption
CWE: CWE-119
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
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: lore.kernel.org

Timelineinfo

12/10/2021 🔍
02/18/2022 +70 days 🔍
02/18/2022 +0 days 🔍
02/18/2022 +0 days 🔍

Sourcesinfo

Vendor: kernel.org

Advisory: bugzilla.redhat.com
Status: Confirmed

CVE: CVE-2021-4090 (🔍)
GCVE (CVE): GCVE-0-2021-4090
GCVE (VulDB): GCVE-100-193340

Entryinfo

Created: 02/18/2022 20:30
Changes: 02/18/2022 20:30 (41)
Complete: 🔍
Cache ID: 216::103