VDB-207384 · CVE-2021-3864 · GCVE-0-2021-3864

Linux Kernel SUID/GUID begin_new_exec permission

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.
7.7	$0-$5k	0.00

Summaryinfo

A vulnerability, which was classified as critical, was found in Linux Kernel. Affected by this issue is the function begin_new_exec of the component SUID/GUID. The manipulation results in permission. This vulnerability is cataloged as CVE-2021-3864. 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 (Operating System) (affected version not known). It has been classified as critical. Affected is the function begin_new_exec of the component SUID/GUID. The manipulation with an unknown input leads to a permission vulnerability. CWE is classifying the issue as CWE-275. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

A flaw was found in the way the dumpable flag setting was handled when certain SUID binaries executed its descendants. The prerequisite is a SUID binary that sets real UID equal to effective UID, and real GID equal to effective GID. The descendant will then have a dumpable value set to 1. As a result, if the descendant process crashes and core_pattern is set to a relative value, its core dump is stored in the current directory with uid:gid permissions. An unprivileged local user with eligible root SUID binary could use this flaw to place core dumps into root-owned directories, potentially resulting in escalation of privileges.

The weakness was shared 08/26/2022. The advisory is shared for download at access.redhat.com. This vulnerability is traded as CVE-2021-3864 since 10/06/2021. 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 10/02/2022). The MITRE ATT&CK project declares the attack technique as T1222.

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

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

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: 7.9
VulDB Meta Temp Score: 7.7

VulDB Base Score: 8.8
VulDB Temp Score: 8.4
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 7.0
NVD Vector: 🔍

CVSSv2info

AV	AC	Au	C	I	A
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💳	💳	💳	💳	💳	💳
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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: Permission
CWE: CWE-275 / CWE-266
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: Patch
Status: 🔍

0-Day Time: 🔍

Patch: lore.kernel.org

Timelineinfo

10/06/2021 🔍
08/26/2022 +324 days 🔍
08/26/2022 +0 days 🔍
10/02/2022 +37 days 🔍

Sourcesinfo

Vendor: kernel.org

Advisory: access.redhat.com
Status: Confirmed

CVE: CVE-2021-3864 (🔍)
GCVE (CVE): GCVE-0-2021-3864
GCVE (VulDB): GCVE-100-207384

Entryinfo

Created: 08/26/2022 20:41
Updated: 10/02/2022 12:17
Changes: 08/26/2022 20:41 (41), 10/02/2022 12:17 (11)
Complete: 🔍
Cache ID: 216::103