CVE-2021-33656
published 2022-07-18CVE-2021-33656: When setting font with malicous data by ioctl cmd PIO_FONT,kernel will write memory out of bounds.
PriorityP427medium6.8CVSS 3.1
AVPACLPRNUINSUCHIHAH
EPSS
0.57%
44.1th percentile
When setting font with malicous data by ioctl cmd PIO_FONT,kernel will write memory out of bounds.
Affected
11 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| debian | debian_linux | — | — |
| debian | linux | < linux 5.14.6-1 (bookworm) | linux 5.14.6-1 (bookworm) |
| linux | linux_kernel | < 5.10.127 | 5.10.127 |
| linux | linux_kernel | >= 0 < 5.10.127-1 | 5.10.127-1 |
| linux | linux_kernel | >= 0 < 5.14.6-1 | 5.14.6-1 |
| linux | linux_kernel | >= 0 < 5.14.6-1 | 5.14.6-1 |
| linux | linux_kernel | >= 0 < 5.14.6-1 | 5.14.6-1 |
| linux | linux_kernel | >= 0 < 5.4.0-125.141 | 5.4.0-125.141 |
| linux | linux_kernel | >= 0 < 4.4.0-234.268 | 4.4.0-234.268 |
| msrc | cm1_kernel_5.10.131.1-1_on_cbl_mariner_1.0 | — | — |
| openatom | openeuler | — | — |
CVSS provenance
nvdv3.16.8MEDIUMCVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
osv6.8MEDIUM
vendor_debian6.8MEDIUM
vendor_msrc6.8MEDIUM
vendor_redhat6.8MEDIUM
vendor_ubuntu6.7MEDIUM
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OSV
linux, linux-aws, linux-kvm, linux-lts-xenial vulnerabilities
osv·2022-09-30·CVSS 6.7
CVE-2021-33655 [MEDIUM] linux, linux-aws, linux-kvm, linux-lts-xenial vulnerabilities
linux, linux-aws, linux-kvm, linux-lts-xenial vulnerabilities
It was discovered that the framebuffer driver on the Linux kernel did not
verify size limits when changing font or screen size, leading to an out-of-
bounds write. A local attacker could use this to cause a denial of service
(system crash) or possibly execute arbitrary code. (CVE-2021-33655)
It was discovered that the virtual terminal driver in the Linux kernel did
not properly handle VGA console font changes, leading to an out-of-bounds
write. A local attacker could use this to cause a denial of service (system
crash) or possibly execute arbitrary code. (CVE-2021-33656)
Christian Brauner discovered that the XFS file system implementation in the
Linux kernel did not properly handle setgid file creation. A local attacker
could
OSV
linux-azure-fde vulnerabilities
osv·2022-09-09·CVSS 5.5
CVE-2021-33061 [MEDIUM] linux-azure-fde vulnerabilities
linux-azure-fde vulnerabilities
Asaf Modelevsky discovered that the Intel(R) 10GbE PCI Express (ixgbe)
Ethernet driver for the Linux kernel performed insufficient control flow
management. A local attacker could possibly use this to cause a denial of
service. (CVE-2021-33061)
It was discovered that the virtual terminal driver in the Linux kernel did
not properly handle VGA console font changes, leading to an out-of-bounds
write. A local attacker could use this to cause a denial of service (system
crash) or possibly execute arbitrary code. (CVE-2021-33656)
OSV
linux-raspi-5.4 vulnerabilities
osv·2022-09-08·CVSS 5.5
CVE-2021-33061 [MEDIUM] linux-raspi-5.4 vulnerabilities
linux-raspi-5.4 vulnerabilities
Asaf Modelevsky discovered that the Intel(R) 10GbE PCI Express (ixgbe)
Ethernet driver for the Linux kernel performed insufficient control flow
management. A local attacker could possibly use this to cause a denial of
service. (CVE-2021-33061)
It was discovered that the virtual terminal driver in the Linux kernel did
not properly handle VGA console font changes, leading to an out-of-bounds
write. A local attacker could use this to cause a denial of service (system
crash) or possibly execute arbitrary code. (CVE-2021-33656)
OSV
linux-hwe-5.4 vulnerabilities
osv·2022-09-05·CVSS 5.5
CVE-2021-33061 [MEDIUM] linux-hwe-5.4 vulnerabilities
linux-hwe-5.4 vulnerabilities
Asaf Modelevsky discovered that the Intel(R) 10GbE PCI Express (ixgbe)
Ethernet driver for the Linux kernel performed insufficient control flow
management. A local attacker could possibly use this to cause a denial of
service. (CVE-2021-33061)
It was discovered that the virtual terminal driver in the Linux kernel did
not properly handle VGA console font changes, leading to an out-of-bounds
write. A local attacker could use this to cause a denial of service (system
crash) or possibly execute arbitrary code. (CVE-2021-33656)
OSV
linux-aws-5.4, linux-azure-5.4 vulnerabilities
osv·2022-09-02·CVSS 5.5
CVE-2021-33061 [MEDIUM] linux-aws-5.4, linux-azure-5.4 vulnerabilities
linux-aws-5.4, linux-azure-5.4 vulnerabilities
Asaf Modelevsky discovered that the Intel(R) 10GbE PCI Express (ixgbe)
Ethernet driver for the Linux kernel performed insufficient control flow
management. A local attacker could possibly use this to cause a denial of
service. (CVE-2021-33061)
It was discovered that the virtual terminal driver in the Linux kernel did
not properly handle VGA console font changes, leading to an out-of-bounds
write. A local attacker could use this to cause a denial of service (system
crash) or possibly execute arbitrary code. (CVE-2021-33656)
OSV
linux-aws, linux-azure, linux-bluefield, linux-gcp, linux-gcp-5.4, linux-gke, linux-gkeop, linux-ibm, linux-ibm-5.4, linux-kvm, linux-oracle, linux-oracle-5.4 vulnerabilities
osv·2022-09-01·CVSS 5.5
CVE-2021-33061 [MEDIUM] linux-aws, linux-azure, linux-bluefield, linux-gcp, linux-gcp-5.4, linux-gke, linux-gkeop, linux-ibm, linux-ibm-5.4, linux-kvm, linux-oracle, linux-oracle-5.4 vulnerabilities
linux-aws, linux-azure, linux-bluefield, linux-gcp, linux-gcp-5.4, linux-gke, linux-gkeop, linux-ibm, linux-ibm-5.4, linux-kvm, linux-oracle, linux-oracle-5.4 vulnerabilities
Asaf Modelevsky discovered that the Intel(R) 10GbE PCI Express (ixgbe)
Ethernet driver for the Linux kernel performed insufficient control flow
management. A local attacker could possibly use this to cause a denial of
service. (CVE-2021-33061)
It was discovered that the virtual terminal driver in the Linux kernel did
not properly handle VGA console font changes, leading to an out-of-bounds
write. A local attacker could use this to cause a denial of service (system
crash) or possibly execute arbitrary code. (CVE-2021-33656)
OSV
linux, linux-raspi vulnerabilities
osv·2022-08-30·CVSS 5.5
CVE-2021-33061 [MEDIUM] linux, linux-raspi vulnerabilities
linux, linux-raspi vulnerabilities
Asaf Modelevsky discovered that the Intel(R) 10GbE PCI Express (ixgbe)
Ethernet driver for the Linux kernel performed insufficient control flow
management. A local attacker could possibly use this to cause a denial of
service. (CVE-2021-33061)
It was discovered that the virtual terminal driver in the Linux kernel did
not properly handle VGA console font changes, leading to an out-of-bounds
write. A local attacker could use this to cause a denial of service (system
crash) or possibly execute arbitrary code. (CVE-2021-33656)
OSV
linux-aws vulnerabilities
osv·2022-08-24·CVSS 6.7
CVE-2021-33655 [MEDIUM] linux-aws vulnerabilities
linux-aws vulnerabilities
It was discovered that the framebuffer driver on the Linux kernel did not
verify size limits when changing font or screen size, leading to an out-of-
bounds write. A local attacker could use this to cause a denial of service
(system crash) or possibly execute arbitrary code. (CVE-2021-33655)
It was discovered that the virtual terminal driver in the Linux kernel did
not properly handle VGA console font changes, leading to an out-of-bounds
write. A local attacker could use this to cause a denial of service (system
crash) or possibly execute arbitrary code. (CVE-2021-33656)
It was discovered that the Packet network protocol implementation in the
Linux kernel contained an out-of-bounds access. A remote attacker could use
this to expose sensitive information (kernel
GHSA
GHSA-9p9r-j677-3r3q: When setting font with malicous data by ioctl cmd PIO_FONT,kernel will write memory out of bounds
ghsa_unreviewed·2022-07-19
CVE-2021-33656 [HIGH] CWE-787 GHSA-9p9r-j677-3r3q: When setting font with malicous data by ioctl cmd PIO_FONT,kernel will write memory out of bounds
When setting font with malicous data by ioctl cmd PIO_FONT,kernel will write memory out of bounds.
OSV
CVE-2021-33656: When setting font with malicous data by ioctl cmd PIO_FONT,kernel will write memory out of bounds
osv·2022-07-18·CVSS 6.8
CVE-2021-33656 [MEDIUM] CVE-2021-33656: When setting font with malicous data by ioctl cmd PIO_FONT,kernel will write memory out of bounds
When setting font with malicous data by ioctl cmd PIO_FONT,kernel will write memory out of bounds.
Ubuntu
Linux kernel vulnerabilities
vendor_ubuntu·2022-09-30·CVSS 6.7
CVE-2021-4037 [MEDIUM] Linux kernel vulnerabilities
Title: Linux kernel vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
It was discovered that the framebuffer driver on the Linux kernel did not
verify size limits when changing font or screen size, leading to an out-of-
bounds write. A local attacker could use this to cause a denial of service
(system crash) or possibly execute arbitrary code. (CVE-2021-33655)
It was discovered that the virtual terminal driver in the Linux kernel did
not properly handle VGA console font changes, leading to an out-of-bounds
write. A local attacker could use this to cause a denial of service (system
crash) or possibly execute arbitrary code. (CVE-2021-33656)
Christian Brauner discovered that the XFS file system implementation in the
Linux kernel did not properly handle setg
Ubuntu
Linux kernel (Azure CVM) vulnerabilities
vendor_ubuntu·2022-09-09·CVSS 5.5
CVE-2021-33656 [MEDIUM] Linux kernel (Azure CVM) vulnerabilities
Title: Linux kernel (Azure CVM) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
Asaf Modelevsky discovered that the Intel(R) 10GbE PCI Express (ixgbe)
Ethernet driver for the Linux kernel performed insufficient control flow
management. A local attacker could possibly use this to cause a denial of
service. (CVE-2021-33061)
It was discovered that the virtual terminal driver in the Linux kernel did
not properly handle VGA console font changes, leading to an out-of-bounds
write. A local attacker could use this to cause a denial of service (system
crash) or possibly execute arbitrary code. (CVE-2021-33656)
Instructions: After a standard system update you need to reboot your computer to make
all the necessary changes.
ATTENTION: Due to an unavoidable ABI cha
Ubuntu
Linux kernel (Raspberry Pi) vulnerabilities
vendor_ubuntu·2022-09-08·CVSS 5.5
CVE-2021-33656 [MEDIUM] Linux kernel (Raspberry Pi) vulnerabilities
Title: Linux kernel (Raspberry Pi) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
Asaf Modelevsky discovered that the Intel(R) 10GbE PCI Express (ixgbe)
Ethernet driver for the Linux kernel performed insufficient control flow
management. A local attacker could possibly use this to cause a denial of
service. (CVE-2021-33061)
It was discovered that the virtual terminal driver in the Linux kernel did
not properly handle VGA console font changes, leading to an out-of-bounds
write. A local attacker could use this to cause a denial of service (system
crash) or possibly execute arbitrary code. (CVE-2021-33656)
Instructions: After a standard system update you need to reboot your computer to make
all the necessary changes.
ATTENTION: Due to an unavoidable ABI
Ubuntu
Linux kernel (HWE) vulnerabilities
vendor_ubuntu·2022-09-05·CVSS 5.5
CVE-2021-33656 [MEDIUM] Linux kernel (HWE) vulnerabilities
Title: Linux kernel (HWE) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
Asaf Modelevsky discovered that the Intel(R) 10GbE PCI Express (ixgbe)
Ethernet driver for the Linux kernel performed insufficient control flow
management. A local attacker could possibly use this to cause a denial of
service. (CVE-2021-33061)
It was discovered that the virtual terminal driver in the Linux kernel did
not properly handle VGA console font changes, leading to an out-of-bounds
write. A local attacker could use this to cause a denial of service (system
crash) or possibly execute arbitrary code. (CVE-2021-33656)
Instructions: After a standard system update you need to reboot your computer to make
all the necessary changes.
ATTENTION: Due to an unavoidable ABI change th
Ubuntu
Linux kernel (Oracle) vulnerability
vendor_ubuntu·2022-09-05
CVE-2021-33656 Linux kernel (Oracle) vulnerability
Title: Linux kernel (Oracle) vulnerability
Summary: The system could be made to crash or run programs as an administrator.
It was discovered that the virtual terminal driver in the Linux kernel did
not properly handle VGA console font changes, leading to an out-of-bounds
write. A local attacker could use this to cause a denial of service (system
crash) or possibly execute arbitrary code.
Instructions: After a standard system update you need to reboot your computer to make
all the necessary changes.
ATTENTION: Due to an unavoidable ABI change the kernel updates have
been given a new version number, which requires you to recompile and
reinstall all third party kernel modules you might have installed.
Unless you manually uninstalled the standard kernel metapackages
(e.g. linux-generic, li
Ubuntu
Linux kernel (AWS) vulnerability
vendor_ubuntu·2022-09-02
CVE-2021-33656 Linux kernel (AWS) vulnerability
Title: Linux kernel (AWS) vulnerability
Summary: The system could be made to crash or run programs as an administrator.
It was discovered that the virtual terminal driver in the Linux kernel did
not properly handle VGA console font changes, leading to an out-of-bounds
write. A local attacker could use this to cause a denial of service (system
crash) or possibly execute arbitrary code.
Instructions: After a standard system update you need to reboot your computer to make
all the necessary changes.
ATTENTION: Due to an unavoidable ABI change the kernel updates have
been given a new version number, which requires you to recompile and
reinstall all third party kernel modules you might have installed.
Unless you manually uninstalled the standard kernel metapackages
(e.g. linux-generic, linux
Ubuntu
Linux kernel vulnerabilities
vendor_ubuntu·2022-09-02·CVSS 5.5
CVE-2021-33656 [MEDIUM] Linux kernel vulnerabilities
Title: Linux kernel vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
Asaf Modelevsky discovered that the Intel(R) 10GbE PCI Express (ixgbe)
Ethernet driver for the Linux kernel performed insufficient control flow
management. A local attacker could possibly use this to cause a denial of
service. (CVE-2021-33061)
It was discovered that the virtual terminal driver in the Linux kernel did
not properly handle VGA console font changes, leading to an out-of-bounds
write. A local attacker could use this to cause a denial of service (system
crash) or possibly execute arbitrary code. (CVE-2021-33656)
Instructions: After a standard system update you need to reboot your computer to make
all the necessary changes.
ATTENTION: Due to an unavoidable ABI change the kern
Ubuntu
Linux kernel (HWE) vulnerability
vendor_ubuntu·2022-09-01
CVE-2021-33656 Linux kernel (HWE) vulnerability
Title: Linux kernel (HWE) vulnerability
Summary: The system could be made to crash or run programs as an administrator.
It was discovered that the virtual terminal driver in the Linux kernel did
not properly handle VGA console font changes, leading to an out-of-bounds
write. A local attacker could use this to cause a denial of service (system
crash) or possibly execute arbitrary code.
Instructions: After a standard system update you need to reboot your computer to make
all the necessary changes.
ATTENTION: Due to an unavoidable ABI change the kernel updates have
been given a new version number, which requires you to recompile and
reinstall all third party kernel modules you might have installed.
Unless you manually uninstalled the standard kernel metapackages
(e.g. linux-generic, linux
Ubuntu
Linux kernel vulnerability
vendor_ubuntu·2022-09-01
CVE-2021-33656 Linux kernel vulnerability
Title: Linux kernel vulnerability
Summary: The system could be made to crash or run programs as an administrator.
It was discovered that the virtual terminal driver in the Linux kernel did
not properly handle VGA console font changes, leading to an out-of-bounds
write. A local attacker could use this to cause a denial of service (system
crash) or possibly execute arbitrary code.
Instructions: After a standard system update you need to reboot your computer to make
all the necessary changes.
ATTENTION: Due to an unavoidable ABI change the kernel updates have
been given a new version number, which requires you to recompile and
reinstall all third party kernel modules you might have installed.
Unless you manually uninstalled the standard kernel metapackages
(e.g. linux-generic, linux-gener
Ubuntu
Linux kernel (AWS) vulnerabilities
vendor_ubuntu·2022-08-24·CVSS 6.7
CVE-2022-36946 [MEDIUM] Linux kernel (AWS) vulnerabilities
Title: Linux kernel (AWS) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
It was discovered that the framebuffer driver on the Linux kernel did not
verify size limits when changing font or screen size, leading to an out-of-
bounds write. A local attacker could use this to cause a denial of service
(system crash) or possibly execute arbitrary code. (CVE-2021-33655)
It was discovered that the virtual terminal driver in the Linux kernel did
not properly handle VGA console font changes, leading to an out-of-bounds
write. A local attacker could use this to cause a denial of service (system
crash) or possibly execute arbitrary code. (CVE-2021-33656)
It was discovered that the Packet network protocol implementation in the
Linux kernel contained an out-of-bound
Microsoft
When setting font with malicous data by ioctl cmd PIO_FONTkernel will write memory out of bounds.
vendor_msrc·2022-07-12·CVSS 6.8
CVE-2021-33656 [MEDIUM] CWE-787 When setting font with malicous data by ioctl cmd PIO_FONTkernel will write memory out of bounds.
When setting font with malicous data by ioctl cmd PIO_FONTkernel will write memory out of bounds.
FAQ: Is Azure Linux the only Microsoft product that includes this open-source library and is therefore potentially affected by this vulnerability?
One of the main benefits to our customers who choose to use the Azure Linux distro is the commitment to keep it up to date with the most recent and most secure versions of the open source libraries with which the distro is composed. Microsoft is committed to transparency in this work which is why we began publishing CSAF/VEX in October 2025. See this blog post for more information. If impact to additional products is identified, we will update the CVE to reflect this.
Mariner: Mariner
openEuler: openEuler
Customer Action Required: Yes
Remediati
Red Hat
kernel: when setting font with malicious data by ioctl PIO_FONT, kernel will write memory out of bounds
vendor_redhat·2021-01-05·CVSS 6.8
CVE-2021-33656 [MEDIUM] CWE-787 kernel: when setting font with malicious data by ioctl PIO_FONT, kernel will write memory out of bounds
kernel: when setting font with malicious data by ioctl PIO_FONT, kernel will write memory out of bounds
When setting font with malicous data by ioctl cmd PIO_FONT,kernel will write memory out of bounds.
An out-of-bounds write flaw was found in the Linux kernel’s console driver functionality in the way a user triggers the ioctl PIO_FONT with malicious data. This flaw allows a local user to crash or potentially escalate their privileges on the system.
Statement: This flaw is rated as a having Moderate impact, because only local user with the access to the VGA device can trigger it.
Mitigation: Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespr
Debian
CVE-2021-33656: linux - When setting font with malicous data by ioctl cmd PIO_FONT,kernel will write mem...
vendor_debian·2021·CVSS 6.8
CVE-2021-33656 [MEDIUM] CVE-2021-33656: linux - When setting font with malicous data by ioctl cmd PIO_FONT,kernel will write mem...
When setting font with malicous data by ioctl cmd PIO_FONT,kernel will write memory out of bounds.
Scope: local
bookworm: resolved (fixed in 5.14.6-1)
bullseye: resolved (fixed in 5.10.127-1)
forky: resolved (fixed in 5.14.6-1)
sid: resolved (fixed in 5.14.6-1)
trixie: resolved (fixed in 5.14.6-1)
No detection rules found.
No public exploits indexed.
No writeups or analysis indexed.
http://www.openwall.com/lists/oss-security/2022/07/19/3https://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git/tree/releases/5.10.127/vt-drop-old-font-ioctls.patchhttps://lists.debian.org/debian-lts-announce/2022/10/msg00000.htmlhttps://www.openeuler.org/en/security/cve/detail.html?id=CVE-2021-33656&packageName=kernelhttp://www.openwall.com/lists/oss-security/2022/07/19/3https://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git/tree/releases/5.10.127/vt-drop-old-font-ioctls.patchhttps://lists.debian.org/debian-lts-announce/2022/10/msg00000.htmlhttps://www.openeuler.org/en/security/cve/detail.html?id=CVE-2021-33656&packageName=kernel
2022-07-18
Published