VDB-217988 · CVE-2021-26328 · GCVE-0-2021-26328

AMD CPU Mode SNP_INIT memory corruption

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.
5.0	$0-$5k	0.00

Summaryinfo

A vulnerability categorized as critical has been discovered in AMD CPU. Affected by this issue is the function SNP_INIT of the component Mode Handler. Such manipulation leads to memory corruption. This vulnerability is listed as CVE-2021-26328. There is no available exploit.

Detailsinfo

A vulnerability was found in AMD CPU (Chip Software) (affected version unknown). It has been rated as critical. Affected by this issue is the function SNP_INIT of the component Mode Handler. The manipulation with an unknown input leads to a memory corruption vulnerability. Using CWE to declare the problem leads to CWE-119. The product performs operations on a memory buffer, but it can read from or write to a memory location that is outside of the intended boundary of the buffer. Impacted is confidentiality, integrity, and availability. CVE summarizes:

Failure to verify the mode of CPU execution at the time of SNP_INIT may lead to a potential loss of memory integrity for SNP guests.

The weakness was presented 01/11/2023. The advisory is shared for download at amd.com. This vulnerability is handled as CVE-2021-26328 since 01/29/2021. There are known technical details, but no exploit is available.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

Chip Software

Vendor

Name

License

commercial

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.0
VulDB Meta Temp Score: 5.0

VulDB Base Score: 5.5
VulDB Temp Score: 5.5
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 4.4
NVD Vector: 🔍

CVSSv2info

AV	AC	Au	C	I	A
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💳	💳	💳	💳	💳	💳
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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

Exploitinginfo

Class: Memory corruption
CWE: CWE-119
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: Partially

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: no mitigation known
Status: 🔍

0-Day Time: 🔍

Timelineinfo

01/29/2021 🔍
01/11/2023 +712 days 🔍
01/11/2023 +0 days 🔍
04/09/2025 +819 days 🔍

Sourcesinfo

Advisory: amd.com
Status: Confirmed

CVE: CVE-2021-26328 (🔍)
GCVE (CVE): GCVE-0-2021-26328
GCVE (VulDB): GCVE-100-217988

Entryinfo

Created: 01/11/2023 14:51
Updated: 04/09/2025 20:39
Changes: 01/11/2023 14:51 (39), 02/01/2023 14:53 (11), 04/09/2025 20:39 (16)
Complete: 🔍
Cache ID: 216::103