Linux Kernel up to 5.14.9 eBPF kernel/bpf/stackmap.c prealloc_elems_and_freelist out-of-bounds write

CVSS Meta Temp Score
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CTI Interest Score
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6.9$0-$5k0.00

Summaryinfo

A vulnerability labeled as critical has been found in Linux Kernel up to 5.14.9. This issue affects the function prealloc_elems_and_freelist of the file kernel/bpf/stackmap.c of the component eBPF. Such manipulation leads to out-of-bounds write. This vulnerability is traded as CVE-2021-41864. The attack may be launched remotely. There is no exploit available. Applying a patch is advised to resolve this issue.

Detailsinfo

A vulnerability was found in Linux Kernel up to 5.14.9 (Operating System) and classified as critical. Affected by this issue is the function prealloc_elems_and_freelist of the file kernel/bpf/stackmap.c of the component eBPF. The manipulation with an unknown input leads to a out-of-bounds write vulnerability. Using CWE to declare the problem leads to CWE-787. The product writes data past the end, or before the beginning, of the intended buffer. Impacted is confidentiality, integrity, and availability. CVE summarizes:

prealloc_elems_and_freelist in kernel/bpf/stackmap.c in the Linux kernel before 5.14.12 allows unprivileged users to trigger an eBPF multiplication integer overflow with a resultant out-of-bounds write.

The weakness was shared 10/02/2021 as 30e29a9a2bc6a4888335a6ede968b75cd329657a. The advisory is shared for download at git.kernel.org. This vulnerability is handled as CVE-2021-41864 since 10/01/2021. There are known technical details, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 235794 (Amazon Linux 2 : kernel (ALASKERNEL-5.4-2025-099)), which helps to determine the existence of the flaw in a target environment.

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

The vulnerability is also documented in the vulnerability database at Tenable (235794). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

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Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.0
VulDB Meta Temp Score: 6.9

VulDB Base Score: 6.3
VulDB Temp Score: 6.0
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 7.8
NVD Vector: 🔍

CVSSv2info

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

NVD Base Score: 🔍

Exploitinginfo

Class: Out-of-bounds write
CWE: CWE-787 / CWE-119
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 235794
Nessus Name: Amazon Linux 2 : kernel (ALASKERNEL-5.4-2025-099)

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Patch
Status: 🔍

0-Day Time: 🔍

Patch: git.kernel.org

Timelineinfo

10/01/2021 🔍
10/02/2021 +1 days 🔍
10/02/2021 +0 days 🔍
08/05/2026 +1768 days 🔍

Sourcesinfo

Vendor: kernel.org

Advisory: 30e29a9a2bc6a4888335a6ede968b75cd329657a
Status: Confirmed

CVE: CVE-2021-41864 (🔍)
GCVE (CVE): GCVE-0-2021-41864
GCVE (VulDB): GCVE-100-183704

Entryinfo

Created: 10/02/2021 07:57
Updated: 08/05/2026 21:09
Changes: 10/02/2021 07:57 (44), 10/08/2021 10:16 (1), 05/13/2025 19:11 (16), 08/05/2026 21:09 (22)
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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