CVE-2020-29661: Use After Free

Published Dec 4, 2020
·
Updated

A locking issue was discovered in the tty subsystem of the Linux kernel in drivers/tty/ttyjobctrl.c which could allow an attacker with a local account to possibly corrupt memory or escalate privileges.

Reference and upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=54ffccbf053b5b6ca4f6e45094b942fab92a25fc

Other sources

A locking issue was discovered in the tty subsystem of the Linux kernel through 5.9.13. drivers/tty/ttyjobctrl.c allows a use-after-free attack against TIOCSPGRP, aka CID-54ffccbf053b.

A locking vulnerability was found in the tty subsystem of the Linux kernel in drivers/tty/ttyjobctrl.c. This flaw allows a local attacker to possibly corrupt memory or escalate privileges. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability.

Affected Software

51 affected componentsFixes available
redhat/kernel<0:2.6.32-754.39.1.el6
0:2.6.32-754.39.1.el6
redhat/kernel-rt<0:3.10.0-1160.21.1.rt56.1158.el7
0:3.10.0-1160.21.1.rt56.1158.el7
redhat/kernel-alt<0:4.14.0-115.35.1.el7a
0:4.14.0-115.35.1.el7a
redhat/kernel<0:3.10.0-1160.21.1.el7
0:3.10.0-1160.21.1.el7
redhat/kernel<0:3.10.0-693.87.1.el7
0:3.10.0-693.87.1.el7
redhat/kernel<0:3.10.0-957.70.1.el7
0:3.10.0-957.70.1.el7
redhat/kernel<0:3.10.0-1062.46.1.el7
0:3.10.0-1062.46.1.el7
redhat/kernel-rt<0:4.18.0-240.15.1.rt7.69.el8_3
0:4.18.0-240.15.1.rt7.69.el8_3
redhat/kernel<0:4.18.0-240.15.1.el8_3
0:4.18.0-240.15.1.el8_3
redhat/kernel<0:4.18.0-147.43.1.el8_1
0:4.18.0-147.43.1.el8_1
redhat/kernel-rt<0:4.18.0-193.46.1.rt13.96.el8_2
0:4.18.0-193.46.1.rt13.96.el8_2
redhat/kernel<0:4.18.0-193.46.1.el8_2
0:4.18.0-193.46.1.el8_2
Google Android
Linux Linux kernel>=2.6.26<4.4.248
Linux Linux kernel>=4.5<4.9.248
Linux Linux kernel>=4.10<4.14.212
Linux Linux kernel>=4.15<4.19.163
Linux Linux kernel>=4.20<5.4.83
Linux Linux kernel>=5.5<5.9.14
Fedoraproject Fedora=32
Fedoraproject Fedora=33
Debian Debian Linux=9.0
Debian Debian Linux=10.0
NetApp Active Iq Unified Manager Vmware Vsphere
Broadcom Fabric Operating System
All of the following
NetApp Solidfire Baseboard Management Controller Firmware
NetApp Solidfire Baseboard Management Controller
All of the following
NetApp H410c Firmware
NetApp H410c
All of the following
NetApp A700s Firmware
NetApp A700s
All of the following
NetApp 8300 Firmware
NetApp 8300
All of the following
NetApp 8700 Firmware
NetApp 8700
All of the following
NetApp A400 Firmware
NetApp A400
Oracle Tekelec Platform Distribution>=7.4.0<=7.7.1
NetApp Solidfire Baseboard Management Controller Firmware
NetApp Solidfire Baseboard Management Controller
NetApp H410c Firmware
NetApp H410c
NetApp A700s Firmware
NetApp A700s
NetApp 8300 Firmware
NetApp 8300
NetApp 8700 Firmware
NetApp 8700
NetApp A400 Firmware
NetApp A400
debian/linux
5.10.223-15.10.234-16.1.129-16.1.135-16.12.25-16.12.27-1

Remediation

Information

Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update as soon as possible.

Event History

Dec 4, 2020
CVE Published
12:00 AM
Dec 9, 2020
CVE Published
via MITRE·04:57 PM
Data Sourced
via MITRE·04:57 PM
Description
Dec 10, 2020
Data Sourced
via Red Hat·05:42 PM
DescriptionSeverityAffected Software
May 3, 2021
Data Sourced
via Android·12:00 AM
SeverityWeaknessAffected Software
Jan 11, 2024
Data Sourced
via Launchpad·11:50 PM
Description
May 6, 2025
Data Sourced
via Ubuntu·04:26 AM
RemedyDescriptionSeverityAffected Software
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Frequently Asked Questions

1

What is the severity of CVE-2020-29661?

CVE-2020-29661 is classified as a high severity vulnerability that could allow an attacker to corrupt memory or escalate privileges.

2

How can I fix CVE-2020-29661?

To mitigate CVE-2020-29661, update your Linux kernel to the patched versions provided by your Linux distribution.

3

What versions of the Linux kernel are affected by CVE-2020-29661?

CVE-2020-29661 affects multiple versions of the Linux kernel, particularly those prior to the patched releases mentioned in your distribution's advisory.

4

Is CVE-2020-29661 exploitable remotely?

CVE-2020-29661 is not considered remotely exploitable; it requires local access to the affected system.

5

Are there any specific distributions affected by CVE-2020-29661?

Yes, CVE-2020-29661 impacts various distributions including Red Hat, Fedora, and Debian.

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