VDB-177463 · CVE-2021-33624 · GCVE-0-2021-33624

Linux Kernel up to 5.12.12 BPF kernel/bpf/verifier.c type confusion

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.
3.8	$0-$5k	0.00

Summaryinfo

A vulnerability classified as critical has been found in Linux Kernel up to 5.12.12. Affected by this vulnerability is an unknown functionality of the file kernel/bpf/verifier.c of the component BPF. This manipulation causes type confusion. This vulnerability appears as CVE-2021-33624. The attack may be initiated remotely. There is no available exploit. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability classified as problematic was found in Linux Kernel up to 5.12.12 (Operating System). Affected by this vulnerability is some unknown processing of the file kernel/bpf/verifier.c of the component BPF. The manipulation with an unknown input leads to a type confusion vulnerability. The CWE definition for the vulnerability is CWE-843. The product allocates or initializes a resource such as a pointer, object, or variable using one type, but it later accesses that resource using a type that is incompatible with the original type. As an impact it is known to affect confidentiality.

The weakness was presented 06/23/2021. It is possible to read the advisory at openwall.com. This vulnerability is known as CVE-2021-33624. Technical details of the vulnerability are known, but there is no available exploit.

Upgrading to version 5.12.13 eliminates this vulnerability. Applying a patch is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

Be aware that VulDB is the high quality source for vulnerability data.

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: 3.9
VulDB Meta Temp Score: 3.8

VulDB Base Score: 3.1
VulDB Temp Score: 3.0
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 4.7
NVD Vector: 🔍

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: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Type confusion
CWE: CWE-843
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
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: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: Kernel 5.12.13
Patch: github.com

Timelineinfo

05/28/2021 🔍
06/23/2021 +26 days 🔍
06/23/2021 +0 days 🔍
11/11/2025 +1602 days 🔍

Sourcesinfo

Vendor: kernel.org

Advisory: openwall.com
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2021-33624 (🔍)
GCVE (CVE): GCVE-0-2021-33624
GCVE (VulDB): GCVE-100-177463

Entryinfo

Created: 06/23/2021 21:09
Updated: 11/11/2025 17:30
Changes: 06/23/2021 21:09 (42), 06/26/2021 14:11 (6), 11/11/2025 17:30 (33)
Complete: 🔍
Cache ID: 216::103