Is CVE-2020-9391 in the CISA KEV catalog?

No. CVE-2020-9391 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2020-9391?

CVE-2020-9391 has a CVSS v3 base score of 5.5 (MEDIUM).

What is the EPSS score for CVE-2020-9391?

CVE-2020-9391 has an EPSS score of 0.50% (39th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2020-9391?

Upgrade linux on debian 11 to 5.5.13-1 or later.

CVE & CISA-KEV Catalog

CVE-2020-9391

MEDIUM

5.5

CVSS v3

NVD

Description

An issue was discovered in the Linux kernel 5.4 and 5.5 through 5.5.6 on the AArch64 architecture. It ignores the top byte in the address passed to the brk system call, potentially moving the memory break downwards when the application expects it to move upwards, aka CID-dcde237319e6. This has been observed to cause heap corruption with the GNU C Library malloc implementation.

CWE-787Out-of-bounds Write

How to fix

Remediation Available

linuxDebian

Fixed in:5.5.13-1CVE-2020-9391

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorLocal

Attack ComplexityLow

Privileges RequiredLow

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityNone

IntegrityNone

AvailabilityHigh

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Exploit Intelligence

0.50%probability of exploitation in 30 days

39thpercentile

Low risk: more likely to be exploited than 39% of all known CVEs.

References

Patch2

Exploit1

openwall.com

Third-Party Advisory1

security.netapp.com

Other references1

lists.fedoraproject.org

Related Vulnerabilities

Other CWE-787 (Out-of-bounds Write) vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2025-22457	Critical	9.0	100%	KEV + Ransom	Fix
CVE-2025-0282	Critical	9.0	100%	KEV + Ransom	-
CVE-2015-3113	Critical	9.8	100%	KEV	Fix
CVE-2021-20038	Critical	9.8	100%	KEV + Ransom	-
CVE-2023-4863	High	8.8	100%	KEV	Fix
CVE-2020-16040	Medium	6.5	100%	-	Fix

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2024-11-21.