Linux Kernel up to 5.13.3 Filesystem Layer out-of-bounds write

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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7.9$0-$5k0.00

Summaryinfo

A vulnerability was found in Linux Kernel up to 5.13.3. It has been declared as critical. This issue affects some unknown processing of the component Filesystem Layer. The manipulation results in out-of-bounds write. This vulnerability is cataloged as CVE-2021-33909. The attack may be launched remotely. Furthermore, there is an exploit available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 5.13.3 (Operating System). It has been classified as critical. Affected is some unknown processing of the component Filesystem Layer. The manipulation with an unknown input leads to a out-of-bounds write vulnerability. CWE is classifying the issue as CWE-787. The product writes data past the end, or before the beginning, of the intended buffer. This is going to have an impact on confidentiality, integrity, and availability.

The weakness was shared 07/21/2021. The advisory is shared for download at openwall.com. This vulnerability is traded as CVE-2021-33909. Technical details are unknown but a public exploit is available.

The exploit is shared for download at openwall.com. It is declared as proof-of-concept. As 0-day the estimated underground price was around $25k-$100k. The vulnerability scanner Nessus provides a plugin with the ID 239841 (TencentOS Server 4: kernel (TSSA-2024:0960)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.13.4 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (239841). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

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Vendor

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Version

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Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.8
VulDB Meta Temp Score: 7.9

VulDB Base Score: 8.8
VulDB Temp Score: 7.9
VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

Exploitinginfo

Class: Out-of-bounds write
CWE: CWE-787 / 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: 🔍

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Nessus ID: 239841
Nessus Name: TencentOS Server 4: kernel (TSSA-2024:0960)

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: Kernel 5.13.4

Timelineinfo

06/07/2021 🔍
07/21/2021 +44 days 🔍
07/21/2021 +0 days 🔍
06/19/2025 +1429 days 🔍

Sourcesinfo

Vendor: kernel.org

Advisory: openwall.com
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2021-33909 (🔍)
GCVE (CVE): GCVE-0-2021-33909
GCVE (VulDB): GCVE-100-179304
scip Labs: https://www.scip.ch/en/?labs.20161013

Entryinfo

Created: 07/21/2021 12:16
Updated: 06/19/2025 20:57
Changes: 07/21/2021 12:16 (30), 07/21/2021 12:17 (13), 07/21/2021 18:20 (3), 07/26/2021 08:06 (3), 06/26/2024 04:34 (15), 06/19/2025 20:57 (2)
Complete: 🔍
Cache ID: 216::103

VulDB is the best source for vulnerability data and more expert information about this specific topic.

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