CVE-2020-28941

MEDIUM

5.5

CVSS v3

Description

An issue was discovered in drivers/accessibility/speakup/spk_ttyio.c in the Linux kernel through 5.9.9. Local attackers on systems with the speakup driver could cause a local denial of service attack, aka CID-d41227544427. This occurs because of an invalid free when the line discipline is used more than once.

CWE-763

How to fix

Remediation Available

linuxDebian

Fixed in:5.9.11-1CVE-2020-28941

linuxUbuntu

Fixed in:4.15.0-136.140USN-4749-1

Fixed in:5.4.0-66.74USN-4750-1

linux-awsUbuntu

Fixed in:4.15.0-1094.101USN-4749-1

Fixed in:5.4.0-1038.40USN-4750-1

linux-aws-5.4Ubuntu

Fixed in:5.4.0-1038.40~18.04.1USN-4750-1

linux-aws-hweUbuntu

Fixed in:4.15.0-1094.101~16.04.1USN-4749-1

linux-azureUbuntu

Fixed in:4.15.0-1108.120~14.04.1USN-4749-1

Fixed in:4.15.0-1108.120~16.04.1USN-4749-1

Fixed in:5.4.0-1040.42USN-4750-1

linux-azure-4.15Ubuntu

Fixed in:4.15.0-1108.120USN-4749-1

linux-azure-5.4Ubuntu

Fixed in:5.4.0-1040.42~18.04.1USN-4750-1

linux-dell300xUbuntu

Fixed in:4.15.0-1012.16USN-4749-1

linux-gcpUbuntu

Fixed in:4.15.0-1093.106~16.04.1USN-4749-1

Fixed in:5.4.0-1037.40USN-4750-1

linux-gcp-4.15Ubuntu

Fixed in:4.15.0-1093.106USN-4749-1

linux-gcp-5.4Ubuntu

Fixed in:5.4.0-1037.40~18.04.1USN-4750-1

linux-gke-4.15Ubuntu

Fixed in:4.15.0-1079.84USN-4749-1

linux-gke-5.4Ubuntu

Fixed in:5.4.0-1036.38~18.04.1USN-4750-1

linux-gkeopUbuntu

Fixed in:5.4.0-1010.11USN-4750-1

linux-gkeop-5.4Ubuntu

Fixed in:5.4.0-1010.11~18.04.1USN-4750-1

linux-hweUbuntu

Fixed in:4.15.0-136.140~16.04.1USN-4749-1

linux-hwe-5.4Ubuntu

Fixed in:5.4.0-66.74~18.04.2USN-4750-1

linux-hwe-5.8Ubuntu

Fixed in:5.8.0-44.50~20.04.1USN-4751-1

linux-image-4.15.0-1012-dell300xUbuntu

Fixed in:4.15.0-1012.16USN-4749-1

linux-image-4.15.0-1065-oracleUbuntu

Fixed in:4.15.0-1065.73~16.04.1USN-4749-1

Fixed in:4.15.0-1065.73USN-4749-1

linux-image-4.15.0-1079-gkeUbuntu

Fixed in:4.15.0-1079.84USN-4749-1

linux-image-4.15.0-1079-raspi2Ubuntu

Fixed in:4.15.0-1079.84USN-4749-1

linux-image-4.15.0-1085-kvmUbuntu

Fixed in:4.15.0-1085.87USN-4749-1

linux-image-4.15.0-1093-gcpUbuntu

Fixed in:4.15.0-1093.106~16.04.1USN-4749-1

Fixed in:4.15.0-1093.106USN-4749-1

linux-image-4.15.0-1094-awsUbuntu

Fixed in:4.15.0-1094.101~16.04.1USN-4749-1

Fixed in:4.15.0-1094.101USN-4749-1

linux-image-4.15.0-1096-snapdragonUbuntu

Fixed in:4.15.0-1096.105USN-4749-1

linux-image-4.15.0-1108-azureUbuntu

Fixed in:4.15.0-1108.120~14.04.1USN-4749-1

Fixed in:4.15.0-1108.120~16.04.1USN-4749-1

Fixed in:4.15.0-1108.120USN-4749-1

linux-image-4.15.0-136-genericUbuntu

Fixed in:4.15.0-136.140~16.04.1USN-4749-1

Fixed in:4.15.0-136.140USN-4749-1

linux-image-4.15.0-136-generic-lpaeUbuntu

Fixed in:4.15.0-136.140~16.04.1USN-4749-1

Fixed in:4.15.0-136.140USN-4749-1

linux-image-4.15.0-136-lowlatencyUbuntu

Fixed in:4.15.0-136.140~16.04.1USN-4749-1

Fixed in:4.15.0-136.140USN-4749-1

linux-image-5.4.0-1010-gkeopUbuntu

Fixed in:5.4.0-1010.11~18.04.1USN-4750-1

Fixed in:5.4.0-1010.11USN-4750-1

linux-image-5.4.0-1029-raspiUbuntu

Fixed in:5.4.0-1029.32~18.04.1USN-4750-1

Fixed in:5.4.0-1029.32USN-4750-1

linux-image-5.4.0-1033-kvmUbuntu

Fixed in:5.4.0-1033.34USN-4750-1

linux-image-5.4.0-1036-gkeUbuntu

Fixed in:5.4.0-1036.38~18.04.1USN-4750-1

linux-image-5.4.0-1037-gcpUbuntu

Fixed in:5.4.0-1037.40~18.04.1USN-4750-1

Fixed in:5.4.0-1037.40USN-4750-1

linux-image-5.4.0-1038-awsUbuntu

Fixed in:5.4.0-1038.40~18.04.1USN-4750-1

Fixed in:5.4.0-1038.40USN-4750-1

linux-image-5.4.0-1038-oracleUbuntu

Fixed in:5.4.0-1038.41~18.04.1USN-4750-1

Fixed in:5.4.0-1038.41USN-4750-1

linux-image-5.4.0-1040-azureUbuntu

Fixed in:5.4.0-1040.42~18.04.1USN-4750-1

Fixed in:5.4.0-1040.42USN-4750-1

linux-image-5.4.0-66-genericUbuntu

Fixed in:5.4.0-66.74~18.04.2USN-4750-1

Fixed in:5.4.0-66.74USN-4750-1

linux-image-5.4.0-66-generic-lpaeUbuntu

Fixed in:5.4.0-66.74~18.04.2USN-4750-1

Fixed in:5.4.0-66.74USN-4750-1

linux-image-5.4.0-66-lowlatencyUbuntu

Fixed in:5.4.0-66.74~18.04.2USN-4750-1

Fixed in:5.4.0-66.74USN-4750-1

linux-image-5.8.0-44-genericUbuntu

Fixed in:5.8.0-44.50~20.04.1USN-4751-1

linux-image-5.8.0-44-generic-lpaeUbuntu

Fixed in:5.8.0-44.50~20.04.1USN-4751-1

linux-image-5.8.0-44-lowlatencyUbuntu

Fixed in:5.8.0-44.50~20.04.1USN-4751-1

linux-image-awsUbuntu

Fixed in:5.4.0.1038.22USN-4750-1

Fixed in:5.4.0.1038.39USN-4750-1

linux-image-aws-hweUbuntu

Fixed in:4.15.0.1094.87USN-4749-1

linux-image-aws-lts-18.04Ubuntu

Fixed in:4.15.0.1094.97USN-4749-1

linux-image-azureUbuntu

Fixed in:4.15.0.1108.81USN-4749-1

Fixed in:4.15.0.1108.99USN-4749-1

Fixed in:5.4.0.1040.20USN-4750-1

Fixed in:5.4.0.1040.38USN-4750-1

linux-image-azure-lts-18.04Ubuntu

Fixed in:4.15.0.1108.81USN-4749-1

linux-image-dell300xUbuntu

Fixed in:4.15.0.1012.14USN-4749-1

linux-image-gcpUbuntu

Fixed in:4.15.0.1093.94USN-4749-1

Fixed in:5.4.0.1037.24USN-4750-1

Fixed in:5.4.0.1037.46USN-4750-1

linux-image-gcp-lts-18.04Ubuntu

Fixed in:4.15.0.1093.111USN-4749-1

linux-image-genericUbuntu

Fixed in:4.15.0.136.123USN-4749-1

Fixed in:5.4.0.66.69USN-4750-1

linux-image-generic-64k-hwe-20.04Ubuntu

Fixed in:5.8.0.44.50~20.04.30USN-4751-1

linux-image-generic-hwe-16.04Ubuntu

Fixed in:4.15.0.136.132USN-4749-1

linux-image-generic-hwe-18.04Ubuntu

Fixed in:5.4.0.66.74~18.04.61USN-4750-1

linux-image-generic-hwe-20.04Ubuntu

Fixed in:5.8.0.44.50~20.04.30USN-4751-1

linux-image-generic-lpaeUbuntu

Fixed in:4.15.0.136.123USN-4749-1

Fixed in:5.4.0.66.69USN-4750-1

linux-image-generic-lpae-hwe-16.04Ubuntu

Fixed in:4.15.0.136.132USN-4749-1

linux-image-generic-lpae-hwe-18.04Ubuntu

Fixed in:5.4.0.66.74~18.04.61USN-4750-1

linux-image-generic-lpae-hwe-20.04Ubuntu

Fixed in:5.8.0.44.50~20.04.30USN-4751-1

linux-image-gkeUbuntu

Fixed in:4.15.0.1093.94USN-4749-1

Fixed in:4.15.0.1079.83USN-4749-1

linux-image-gke-4.15Ubuntu

Fixed in:4.15.0.1079.83USN-4749-1

linux-image-gke-5.4Ubuntu

Fixed in:5.4.0.1036.38~18.04.4USN-4750-1

linux-image-gkeopUbuntu

Fixed in:5.4.0.1010.13USN-4750-1

linux-image-gkeop-5.4Ubuntu

Fixed in:5.4.0.1010.11~18.04.11USN-4750-1

Fixed in:5.4.0.1010.13USN-4750-1

linux-image-kvmUbuntu

Fixed in:4.15.0.1085.81USN-4749-1

Fixed in:5.4.0.1033.31USN-4750-1

linux-image-lowlatencyUbuntu

Fixed in:4.15.0.136.123USN-4749-1

Fixed in:5.4.0.66.69USN-4750-1

linux-image-lowlatency-hwe-16.04Ubuntu

Fixed in:4.15.0.136.132USN-4749-1

linux-image-lowlatency-hwe-18.04Ubuntu

Fixed in:5.4.0.66.74~18.04.61USN-4750-1

linux-image-lowlatency-hwe-20.04Ubuntu

Fixed in:5.8.0.44.50~20.04.30USN-4751-1

linux-image-oemUbuntu

Fixed in:4.15.0.136.132USN-4749-1

Fixed in:5.4.0.66.74~18.04.61USN-4750-1

Fixed in:5.4.0.66.69USN-4750-1

linux-image-oem-osp1Ubuntu

Fixed in:5.4.0.66.74~18.04.61USN-4750-1

Fixed in:5.4.0.66.69USN-4750-1

linux-image-oracleUbuntu

Fixed in:4.15.0.1065.53USN-4749-1

Fixed in:5.4.0.1038.41~18.04.21USN-4750-1

Fixed in:5.4.0.1038.35USN-4750-1

linux-image-oracle-lts-18.04Ubuntu

Fixed in:4.15.0.1065.75USN-4749-1

linux-image-raspiUbuntu

Fixed in:5.4.0.1029.64USN-4750-1

linux-image-raspi-hwe-18.04Ubuntu

Fixed in:5.4.0.1029.32USN-4750-1

linux-image-raspi2Ubuntu

Fixed in:4.15.0.1079.76USN-4749-1

Fixed in:5.4.0.1029.64USN-4750-1

linux-image-snapdragonUbuntu

Fixed in:4.15.0.1096.99USN-4749-1

linux-image-snapdragon-hwe-18.04Ubuntu

Fixed in:5.4.0.66.74~18.04.61USN-4750-1

linux-image-virtualUbuntu

Fixed in:4.15.0.136.123USN-4749-1

Fixed in:5.4.0.66.69USN-4750-1

linux-image-virtual-hwe-16.04Ubuntu

Fixed in:4.15.0.136.132USN-4749-1

linux-image-virtual-hwe-18.04Ubuntu

Fixed in:5.4.0.66.74~18.04.61USN-4750-1

linux-image-virtual-hwe-20.04Ubuntu

Fixed in:5.8.0.44.50~20.04.30USN-4751-1

linux-kvmUbuntu

Fixed in:4.15.0-1085.87USN-4749-1

Fixed in:5.4.0-1033.34USN-4750-1

linux-oracleUbuntu

Fixed in:4.15.0-1065.73~16.04.1USN-4749-1

Fixed in:4.15.0-1065.73USN-4749-1

Fixed in:5.4.0-1038.41USN-4750-1

linux-oracle-5.4Ubuntu

Fixed in:5.4.0-1038.41~18.04.1USN-4750-1

linux-raspiUbuntu

Fixed in:5.4.0-1029.32USN-4750-1

linux-raspi-5.4Ubuntu

Fixed in:5.4.0-1029.32~18.04.1USN-4750-1

linux-raspi2Ubuntu

Fixed in:4.15.0-1079.84USN-4749-1

linux-snapdragonUbuntu

Fixed in:4.15.0-1096.105USN-4749-1

TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works

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

0.33%probability of exploitation in 30 days

26thpercentile

Low risk: more likely to be exploited than 26% of all known CVEs.

References

Patch5

Third-Party Advisory1

lists.debian.org

Other references2

Related Vulnerabilities

Other CWE-763 vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2007-4367	High	9.3	8.2%	-	Fix
CVE-2015-2695	Medium	5.0	6.2%	-	Fix
CVE-2013-4695	High	7.8	5.3%	-	-
CVE-2020-36224	High	7.5	4.3%	-	Fix
CVE-2022-31625	High	8.1	3.4%	-	Fix
CVE-2021-42377	Critical	9.8	3.4%	-	Fix

Common questions

How do I fix CVE-2020-28941?

Published advisories record a fix for 92 affected products. The "How to fix" section on this page lists the fixed version and source advisory for each one, so apply the entry matching what you actually run.

Is CVE-2020-28941 being actively exploited?

Not that we know of. CVE-2020-28941 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 0.33% is the estimated probability that it will be exploited in the next 30 days. That is higher than 26% of all scored CVEs.

How severe is CVE-2020-28941?

CVE-2020-28941 has a CVSS v3 base score of 5.5, rated medium. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.

What does CVE-2020-28941 affect?

Published advisories record a fix for linux (Debian), linux (Ubuntu), linux-aws (Ubuntu), linux-aws-5.4 (Ubuntu), and 88 more. Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.

Embed a live status badge for CVE-2020-28941

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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 2026-05-29.