Insyde InsydeH2O prior 05.51.23 Kernel CommBuffer/CommBufferSize buffer overflow

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.
8.1$0-$5k0.00

Summaryinfo

A vulnerability classified as critical was found in Insyde InsydeH2O. The impacted element is an unknown function of the component Kernel. Executing a manipulation of the argument CommBuffer/CommBufferSize can lead to buffer overflow. This vulnerability is tracked as CVE-2021-33626. The attack can be launched remotely. No exploit exists. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in Insyde InsydeH2O. It has been declared as critical. This vulnerability affects an unknown function of the component Kernel. The manipulation of the argument CommBuffer/CommBufferSize with an unknown input leads to a buffer overflow vulnerability. The CWE definition for the vulnerability is CWE-120. The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer, leading to a buffer overflow. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

A vulnerability exists in SMM (System Management Mode) branch that registers a SWSMI handler that does not sufficiently check or validate the allocated buffer pointer(QWORD values for CommBuffer). This can be used by an attacker to corrupt data in SMRAM memory and even lead to arbitrary code execution.

The weakness was disclosed 10/01/2021 as SA-2021001. The advisory is shared for download at insyde.com. This vulnerability was named CVE-2021-33626 since 05/28/2021. There are known technical details, but no exploit is available.

Upgrading to version 05.08.23, 05.16.23, 05.26.23, 05.35.23, 05.43.23 or 05.51.23 eliminates this vulnerability.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Vendor

Name

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.3
VulDB Meta Temp Score: 8.1

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

NVD Base Score: 7.8
NVD Vector: 🔍

CVSSv2info

AVACAuCIA
💳💳💳💳💳💳
💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock

VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Buffer overflow
CWE: CWE-120 / CWE-119
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-DayUnlockUnlockUnlockUnlock
TodayUnlockUnlockUnlockUnlock

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: InsydeH2O 05.08.23/05.16.23/05.26.23/05.35.23/05.43.23/05.51.23

Timelineinfo

05/28/2021 🔍
10/01/2021 +126 days 🔍
10/01/2021 +0 days 🔍
11/04/2025 +1495 days 🔍

Sourcesinfo

Advisory: SA-2021001
Status: Confirmed

CVE: CVE-2021-33626 (🔍)
GCVE (CVE): GCVE-0-2021-33626
GCVE (VulDB): GCVE-100-183652

Entryinfo

Created: 10/01/2021 07:26
Updated: 11/04/2025 22:58
Changes: 10/01/2021 07:26 (40), 10/04/2021 15:36 (1), 11/04/2025 22:58 (34)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

Discussion

No comments yet. Languages: en.

Please log in to comment.

◂ PreviousOverviewNext ▸

Might our Artificial Intelligence support you?

Check our Alexa App!