Summary
Daniel Axtens discovered that specially crafted images could cause a
heap-based out-of-bonds write. A local attacker could possibly use
this to circumvent secure boot protections. (CVE-2021-3695)
Daniel Axtens discovered that specially crafted images could cause
out-of-bonds read and write. A local attacker could possibly use this
to circumvent secure boot protections. (CVE-2021-3696)
Daniel Axtens discovered that specially crafted images could cause
buffer underwrite which allows arbitrary data to be written to a heap.
A local attacker could possibly use this to circumvent secure
boot protections. (CVE-2021-3697)
It was discovered that GRUB2 configuration files were created with
the wrong permissions. An attacker could possibly use this to leak
encrypted passwords. (CVE-2021-3981)
Daniel Axtens discovered that specially crafted IP packets could cause
an integer underflow and write past the end of a buffer. An attacker
could possibly use this to circumvent secure boot protections.
(CVE-2022-28733)
Daniel Axtens discovered that specially crafted HTTP headers can cause
an out-of-bounds write of a NULL byte. An attacker could possibly use
this to corrupt GRUB2's internal data. (CVE-2022-28734)
Julian Andres Klode discovered that GRUB2 shim_lock allowed non-
kernel files to be loaded. A local attack could possibly use this to
circumvent secure boot protections. (CVE-2022-28735)
Chris Coulson discovered that executing chainloaders more than once
caused a use-after-free vulnerability. A local attack could possibly
use this to circumvent secure boot protections. (CVE-2022-28736)
Chris Coulson discovered that specially crafted executables could
cause shim to make out-of-bound writes. A local attack could possibly
use this to circumvent secure boot protections. (CVE-2022-28737)
Zhang Boyang discovered that specially crafted unicode sequences
could lead to an out-of-bounds write to a heap. A local attacker could
possibly use this to circumvent secure boot protections.
(CVE-2022-3775)
Fixed packages 8
| Release | Package | Fixed in |
|---|---|---|
| Ubuntu · 20.04 LTS 20.04:LTS | grub2-signed | 1.187.3~20.04.1 |
| Ubuntu · 20.04 LTS 20.04:LTS | grub2-unsigned | 2.06-2ubuntu14.1 |
| Ubuntu · 20.04 LTS 20.04:LTS | shim | 15.7-0ubuntu1 |
| Ubuntu · 20.04 LTS 20.04:LTS | shim-signed | 1.40.9 |
| Ubuntu · 22.04 LTS 22.04:LTS | grub2-signed | 1.187.3~22.04.1 |
| Ubuntu · 22.04 LTS 22.04:LTS | grub2-unsigned | 2.06-2ubuntu14.1 |
| Ubuntu · 22.04 LTS 22.04:LTS | shim | 15.7-0ubuntu1 |
| Ubuntu · 22.04 LTS 22.04:LTS | shim-signed | 1.51.3 |
Vulnerabilities 10
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High 8.1
Integer underflow in grub_net_recv_ip4_packets
Integer underflow in grub_net_recv_ip4_packets; A malicious crafted IP packet can lead to an integer underflow in grub_net_recv_ip4_packets() function on rsm->total_len value. Under certain circumstances the total_len value may end up wrapping around to a sma…
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High 8.1
Out-of-bounds write when handling split HTTP headers
Out-of-bounds write when handling split HTTP headers; When handling split HTTP headers, GRUB2 HTTP code accidentally moves its internal data buffer point by one position. This can lead to a out-of-bound write further when parsing the HTTP request, writing a N…
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High 7.1
When rendering certain unicode sequences, grub2's font code doesn't proper validate if the informed glyph's width and h…
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Medium 6.7
The GRUB2's shim_lock verifier allows non-kernel files to be loaded on shim-powered secure boot systems. Allowing such …
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Medium 6.5
There's a possible overflow in handle_image() when shim tries to load and execute crafted EFI executables
There's a possible overflow in handle_image() when shim tries to load and execute crafted EFI executables; The handle_image() function takes into account the SizeOfRawData field from each section to be loaded. An attacker can leverage this to perform out-of-b…
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Medium 6.4
There's a use-after-free vulnerability in grub_cmd_chainloader() function
There's a use-after-free vulnerability in grub_cmd_chainloader() function; The chainloader command is used to boot up operating systems that doesn't support multiboot and do not have direct support from GRUB2. When executing chainloader more than once a use-a…
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Unscored —
A crafted 16-bit grayscale PNG image may lead to a out-of-bounds write in the heap area. An attacker may take advantage…
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Unscored —
A heap out-of-bounds write may heppen during the handling of Huffman tables in the PNG reader. This may lead to data co…
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Unscored —
A crafted JPEG image may lead the JPEG reader to underflow its data pointer, allowing user-controlled data to be writte…
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Unscored —
A flaw in grub2 was found where its configuration file, known as grub.cfg, is being created with the wrong permission s…
References
-
report
https://ubuntu.com/security/CVE-2021-3695
-
report
https://ubuntu.com/security/CVE-2021-3696
-
report
https://ubuntu.com/security/CVE-2021-3697
-
report
https://ubuntu.com/security/CVE-2021-3981
-
report
https://ubuntu.com/security/CVE-2022-3775
-
report
https://ubuntu.com/security/CVE-2022-28733
-
report
https://ubuntu.com/security/CVE-2022-28734
-
report
https://ubuntu.com/security/CVE-2022-28735
-
report
https://ubuntu.com/security/CVE-2022-28736
-
report
https://ubuntu.com/security/CVE-2022-28737
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report
https://launchpad.net/bugs/2029518