A flaw was found in grub2. When reading tar files, grub2 allocates an internal buffer for the file name. However, it fails to properly verify the allocation against possible integer overflows. It's possible to cause the allocation length to overflow with a crafted tar file, leading to a heap out-of-bounds write. This flaw eventually allows an attacker to circumvent secure boot protections.
CVSS Score
6.7
EPSS Score
0.003
Published
2025-03-03
A flaw was found in grub2. The calculation of the translation buffer when reading a language .mo file in grub_gettext_getstr_from_position() may overflow, leading to a Out-of-bound write. This issue can be leveraged by an attacker to overwrite grub2's sensitive heap data, eventually leading to the circumvention of secure boot protections.
CVSS Score
6.7
EPSS Score
0.002
Published
2025-02-19
GNU GRUB (aka GRUB2) through 2.12 has a heap-based buffer overflow in fs/hfs.c via crafted sblock data in an HFS filesystem.
CVSS Score
8.8
EPSS Score
0.007
Published
2024-12-29
GNU GRUB (aka GRUB2) through 2.12 does not use a constant-time algorithm for grub_crypto_memcmp and thus allows side-channel attacks.
CVSS Score
5.3
EPSS Score
0.004
Published
2024-12-29
GRUB2 does not call the module fini functions on exit, leading to Debian/Ubuntu's peimage GRUB2 module leaving UEFI system table hooks after exit. This lead to a use-after-free condition, and could possibly lead to secure boot bypass.
CVSS Score
6.7
EPSS Score
0.004
Published
2024-04-05
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 small integer number which will be used in memory allocation. If the attack succeeds in such way, subsequent operations can write past the end of the buffer.
CVSS Score
8.1
EPSS Score
0.013
Published
2023-07-20
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 NULL byte past the buffer. It's conceivable that an attacker controlled set of packets can lead to corruption of the GRUB2's internal memory metadata.
CVSS Score
8.1
EPSS Score
0.011
Published
2023-07-20
The GRUB2's shim_lock verifier allows non-kernel files to be loaded on shim-powered secure boot systems. Allowing such files to be loaded may lead to unverified code and modules to be loaded in GRUB2 breaking the secure boot trust-chain.
CVSS Score
6.7
EPSS Score
0.003
Published
2023-07-20
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-after-free vulnerability is triggered. If an attacker can control the GRUB2's memory allocation pattern sensitive data may be exposed and arbitrary code execution can be achieved.
CVSS Score
6.4
EPSS Score
0.003
Published
2023-07-20
When rendering certain unicode sequences, grub2's font code doesn't proper validate if the informed glyph's width and height is constrained within bitmap size. As consequence an attacker can craft an input which will lead to a out-of-bounds write into grub2's heap, leading to memory corruption and availability issues. Although complex, arbitrary code execution could not be discarded.
CVSS Score
7.1
EPSS Score
0.009
Published
2022-12-19