Vulnerability Monitor

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CVE-2021-27379

An issue was discovered in Xen through 4.11.x, allowing x86 Intel HVM guest OS users to achieve unintended read/write DMA access, and possibly cause a denial of service (host OS crash) or gain privileges. This occurs because a backport missed a flush, and thus IOMMU updates were not always correct. NOTE: this issue exists because of an incomplete fix for CVE-2020-15565.

Security Impact Summary

This vulnerability carries a HIGH severity rating with a CVSS v3.1 score of 7.8, requiring local system access to exploit with relatively low complexity without requiring user interaction requiring only low-level privileges . The vulnerability impacts confidentiality (data exposure), integrity (unauthorized modifications), and availability (service disruption) for affected systems. Impacting 2 products from xen, from debian organizations running these solutions should prioritize assessment and patching.

Historical Context

Reported in 2021, this vulnerability emerged during an era marked by increased sophistication in supply chain attacks, cloud infrastructure vulnerabilities, and software-as-a-service (SaaS) security challenges. Security practices during this period emphasized zero-trust architectures, container security, and API protection.

Published

2021-02-18T17:15:15.867

Last Modified

2024-11-21T05:57:52.597

Status

Modified

Source

[email protected]

Severity

CVSSv3.1: 7.8 (HIGH)

CVSSv2 Vector

AV:L/AC:M/Au:N/C:P/I:P/A:C

Access Vector: LOCAL
Access Complexity: MEDIUM
Authentication: NONE
Confidentiality Impact: PARTIAL
Integrity Impact: PARTIAL
Availability Impact: COMPLETE

Exploitability Score

3.4

Impact Score

8.5

Weaknesses

Type: Primary
NVD-CWE-Other

Affected Vendors & Products

Type	Vendor	Product	Version/Range	Vulnerable?
Operating System	xen	xen	< 4.12.0	Yes
Operating System	debian	debian_linux	10.0	Yes

References

http://www.openwall.com/lists/oss-security/2021/02/23/1 Mailing List, Third Party Advisory ([email protected])
http://xenbits.xen.org/xsa/advisory-366.html Mitigation, Patch, Vendor Advisory ([email protected])
https://www.debian.org/security/2021/dsa-4888 Third Party Advisory ([email protected])
https://xenbits.xen.org/xsa/advisory-366.html Patch, Vendor Advisory ([email protected])
http://www.openwall.com/lists/oss-security/2021/02/23/1 Mailing List, Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
http://xenbits.xen.org/xsa/advisory-366.html Mitigation, Patch, Vendor Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://www.debian.org/security/2021/dsa-4888 Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://xenbits.xen.org/xsa/advisory-366.html Patch, Vendor Advisory (af854a3a-2127-422b-91ae-364da2661108)

How SecUtils Interprets This CVE

SecUtils normalizes and enriches National Vulnerability Database (NVD) records by standardizing vendor and product identifiers, aggregating vulnerability metadata from both NVD and MITRE sources, and providing structured context for security teams. For xen's affected products, we extract Common Platform Enumeration (CPE) data, Common Weakness Enumeration (CWE) classifications, CVSS severity metrics, and reference data to enable rapid vulnerability prioritization and asset correlation. This record contains no exploit code, proof-of-concept instructions, or attack methodologies—only defensive intelligence necessary for patch management, risk assessment, and security operations.