VDB-228512 · CVE-2021-26371 · GCVE-0-2021-26371

AMD EPYC System Call information disclosure

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.
4.8	$0-$5k	0.00

Summaryinfo

A vulnerability was found in AMD EPYC and classified as problematic. This impacts an unknown function of the component System Call Handler. Such manipulation leads to information disclosure. This vulnerability is uniquely identified as CVE-2021-26371. No exploit exists.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in AMD EPYC (the affected version is unknown). Affected by this issue is an unknown code of the component System Call Handler. The manipulation with an unknown input leads to a information disclosure vulnerability. Using CWE to declare the problem leads to CWE-200. The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information. Impacted is confidentiality. CVE summarizes:

A compromised or malicious ABL or UApp could send a SHA256 system call to the bootloader, which may result in exposure of ASP memory to userspace, potentially leading to information disclosure.

The weakness was disclosed 05/09/2023. The advisory is shared for download at amd.com. This vulnerability is handled as CVE-2021-26371 since 01/29/2021. There are neither technical details nor an exploit publicly available. The MITRE ATT&CK project declares the attack technique as T1592.

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

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

Productinfo

Vendor

Name

EPYC

License

commercial

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 4.8
VulDB Meta Temp Score: 4.8

VulDB Base Score: 3.5
VulDB Temp Score: 3.5
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 5.5
NVD Vector: 🔍

CNA Base Score: 5.5
CNA 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: 🔍

Exploitinginfo

Class: Information disclosure
CWE: CWE-200 / CWE-284 / CWE-266
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 🔍
05/09/2023 +829 days 🔍
05/09/2023 +0 days 🔍
01/28/2025 +630 days 🔍

Sourcesinfo

Advisory: amd.com
Status: Confirmed

CVE: CVE-2021-26371 (🔍)
GCVE (CVE): GCVE-0-2021-26371
GCVE (VulDB): GCVE-100-228512

Entryinfo

Created: 05/09/2023 23:39
Updated: 01/28/2025 17:25
Changes: 05/09/2023 23:39 (37), 06/01/2023 20:31 (11), 01/28/2025 17:25 (26)
Complete: 🔍
Cache ID: 216::103