VDB-338219 · CVE-2023-54021 · Nessus 279936

Linux Kernel up to 6.3.3 ext4 ext4_get_group_no_and_offset initialization

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.
5.3	$0-$5k	0.00

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.3.3. It has been rated as critical. This affects the function ext4_get_group_no_and_offset of the component ext4. The manipulation leads to initialization. This vulnerability is traded as CVE-2023-54021. There is no exploit available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.3.3. It has been rated as critical. This issue affects the function ext4_get_group_no_and_offset of the component ext4. The manipulation with an unknown input leads to a initialization vulnerability. Using CWE to declare the problem leads to CWE-665. The product does not initialize or incorrectly initializes a resource, which might leave the resource in an unexpected state when it is accessed or used. The impact remains unknown. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: ext4: set goal start correctly in ext4_mb_normalize_request We need to set ac_g_ex to notify the goal start used in ext4_mb_find_by_goal. Set ac_g_ex instead of ac_f_ex in ext4_mb_normalize_request. Besides we should assure goal start is in range [first_data_block, blocks_count) as ext4_mb_initialize_context does. [ Added a check to make sure size is less than ar->pright; otherwise we could end up passing an underflowed value of ar->pright - size to ext4_get_group_no_and_offset(), which will trigger a BUG_ON later on. - TYT ]

It is possible to read the advisory at git.kernel.org. The identification of this vulnerability is CVE-2023-54021 since 12/24/2025. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 12/26/2025).

The vulnerability scanner Nessus provides a plugin with the ID 279936 (Linux Distros Unpatched Vulnerability : CVE-2023-54021), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 4.14.316, 4.19.284, 5.4.244, 5.10.181, 5.15.113, 6.1.30 or 6.3.4 eliminates this vulnerability. Applying the patch 2479bb6cbdb4d56b807bbe5229e3e26a6f1f4530/390eee955d4de4662db5e3e9e9a9eae020432cb7/cee78217a7ae72d11c2e21e1a5263b8044489823/3ca3005b502ca8ea87d6a344323b179b48c4e4a3/bc4a3e1d07a86ae5845321d371190244acacb2f2/c6bee8970075b256fc1b07bf4873049219380818/abb330ffaa3a0ae7ce632e28c9260b461c01f19f/b07ffe6927c75d99af534d685282ea188d9f71a6 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.

The vulnerability is also documented in the databases at Tenable (279936) and CERT Bund (WID-SEC-2025-2920). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Affected

Open Source Linux Kernel

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: 5.5
VulDB Meta Temp Score: 5.3

VulDB Base Score: 5.5
VulDB Temp Score: 5.3
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AV	AC	Au	C	I	A
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💳	💳	💳	💳	💳	💳
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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Initialization
CWE: CWE-665
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 279936
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2023-54021

Threat Intelligenceinfo

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

Countermeasuresinfo

Timelineinfo

12/24/2025 Advisory disclosed
12/24/2025 +0 days CVE reserved
12/24/2025 +0 days VulDB entry created
12/26/2025 +2 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2023-54021 (🔒)
GCVE (CVE): GCVE-0-2023-54021
GCVE (VulDB): GCVE-100-338219
CERT Bund: WID-SEC-2025-2920 - Linux Kernel: Mehrere Schwachstellen

Entryinfo

Created: 12/24/2025 15:31
Updated: 12/26/2025 08:40
Changes: 12/24/2025 15:31 (59), 12/25/2025 08:57 (7), 12/26/2025 08:40 (2)
Complete: 🔍
Cache ID: 216::103

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