A buffer overflow was found in grub_font_construct_glyph(). A malicious crafted pf2 font can lead to an overflow when calculating the max_glyph_size value, allocating a smaller than needed buffer for the glyph, this further leads to a buffer overflow and a heap based out-of-bounds write. An attacker may use this vulnerability to circumvent the secure boot mechanism.
CVSS Score
8.6
EPSS Score
0.001
Published
2022-12-14
A crafted 16-bit grayscale PNG image may lead to a out-of-bounds write in the heap area. An attacker may take advantage of that to cause heap data corruption or eventually arbitrary code execution and circumvent secure boot protections. This issue has a high complexity to be exploited as an attacker needs to perform some triage over the heap layout to achieve signifcant results, also the values written into the memory are repeated three times in a row making difficult to produce valid payloads. This flaw affects grub2 versions prior grub-2.12.
CVSS Score
4.5
EPSS Score
0.001
Published
2022-07-06
A heap out-of-bounds write may heppen during the handling of Huffman tables in the PNG reader. This may lead to data corruption in the heap space. Confidentiality, Integrity and Availablity impact may be considered Low as it's very complex to an attacker control the encoding and positioning of corrupted Huffman entries to achieve results such as arbitrary code execution and/or secure boot circumvention. This flaw affects grub2 versions prior grub-2.12.
CVSS Score
4.5
EPSS Score
0.001
Published
2022-07-06
A crafted JPEG image may lead the JPEG reader to underflow its data pointer, allowing user-controlled data to be written in heap. To a successful to be performed the attacker needs to perform some triage over the heap layout and craft an image with a malicious format and payload. This vulnerability can lead to data corruption and eventual code execution or secure boot circumvention. This flaw affects grub2 versions prior grub-2.12.
CVSS Score
7.0
EPSS Score
0.001
Published
2022-07-06
A Insecure Temporary File vulnerability in grub-once of grub2 in SUSE Linux Enterprise Server 15 SP4, openSUSE Factory allows local attackers to truncate arbitrary files. This issue affects: SUSE Linux Enterprise Server 15 SP4 grub2 versions prior to 2.06-150400.7.1. SUSE openSUSE Factory grub2 versions prior to 2.06-18.1.
CVSS Score
5.1
EPSS Score
0.0
Published
2022-03-16
A flaw in grub2 was found where its configuration file, known as grub.cfg, is being created with the wrong permission set allowing non privileged users to read its content. This represents a low severity confidentiality issue, as those users can eventually read any encrypted passwords present in grub.cfg. This flaw affects grub2 2.06 and previous versions. This issue has been fixed in grub upstream but no version with the fix is currently released.
CVSS Score
3.3
EPSS Score
0.0
Published
2022-03-10
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