CVE-2025-0677 — Out-of-bounds Write in Debian Grub2

Vendor	Product	Version range	Fixed in
debian	grub2	< grub2 2.12-6 (forky)	grub2 2.12-6 (forky)
gnu	grub2	>= 0 < 2.12-6	2.12-6
gnu	grub2	>= 0 < 2.12-6	2.12-6
msrc	azl3_grub2_2.06-24_on_azure_linux_3.0	—	—
msrc	azl3_grub2_2.06-25_on_azure_linux_3.0	—	—
msrc	cbl2_grub2_2.06-14_on_cbl_mariner_2.0	—	—
msrc	cbl2_grub2_2.06-15_on_cbl_mariner_2.0	—	—

Red Hat

grub2: UFS: Integer overflow may lead to heap based out-of-bounds write when handling symlinks

vendor_redhat·2025-02-18·CVSS 6.4

CVE-2025-0677 [MEDIUM] CWE-787 grub2: UFS: Integer overflow may lead to heap based out-of-bounds write when handling symlinks grub2: UFS: Integer overflow may lead to heap based out-of-bounds write when handling symlinks A flaw was found in grub2. When performing a symlink lookup, the grub's UFS module checks the inode's data size to allocate the internal buffer to read the file content, however, it fails to check if the symlink data size has overflown. When this occurs, grub_malloc() may be called with a smaller value than needed. When further reading the data from the disk into the buffer, the grub_ufs_lookup_symlink() function will write past the end of the allocated size. An attack can leverage this by crafting a malicious filesystem, and as a result, it will corrupt data stored in the heap, allowing for arbitrary code execution used to by-pass secure boot mechanisms. A flaw was found in grub2. When perform

Microsoft

Grub2: ufs: integer overflow may lead to heap based out-of-bounds write when handling symlinks

vendor_msrc·2025-02-11·CVSS 6.4

CVE-2025-0677 [MEDIUM] CWE-787 Grub2: ufs: integer overflow may lead to heap based out-of-bounds write when handling symlinks Grub2: ufs: integer overflow may lead to heap based out-of-bounds write when handling symlinks 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 redhat: redhat Customer Action Required: Yes Remediation: CBL-M

Debian

CVE-2025-0677: grub2 - A flaw was found in grub2. When performing a symlink lookup, the grub's UFS modu...

vendor_debian·2025·CVSS 6.4

CVE-2025-0677 [MEDIUM] CVE-2025-0677: grub2 - A flaw was found in grub2. When performing a symlink lookup, the grub's UFS modu... A flaw was found in grub2. When performing a symlink lookup, the grub's UFS module checks the inode's data size to allocate the internal buffer to read the file content, however, it fails to check if the symlink data size has overflown. When this occurs, grub_malloc() may be called with a smaller value than needed. When further reading the data from the disk into the buffer, the grub_ufs_lookup_symlink() function will write past the end of the allocated size. An attack can leverage this by crafting a malicious filesystem, and as a result, it will corrupt data stored in the heap, allowing for arbitrary code execution used to by-pass secure boot mechanisms. Scope: local bookworm: open bullseye: open forky: resolved (fixed in 2.12-6) sid: resolved (fixed in 2.12-6) trixie: resolved (fixed in

GHSA

GHSA-h592-gmp8-rvr7: A flaw was found in grub2

ghsa_unreviewed·2025-02-19

CVE-2025-0677 [MEDIUM] CWE-787 GHSA-h592-gmp8-rvr7: A flaw was found in grub2 A flaw was found in grub2. When performing a symlink lookup, the grub's UFS module checks the inode's data size to allocate the internal buffer to read the file content, however, it fails to check if the symlink data size has overflown. When this occurs, grub_malloc() may be called with a smaller value than needed. When further reading the data from the disk into the buffer, the grub_ufs_lookup_symlink() function will write past the end of the allocated size. An attack can leverage this by crafting a malicious filesystem, and as a result, it will corrupt data stored in the heap, allowing for arbitrary code execution used to by-pass secure boot mechanisms.

OSV

CVE-2025-0677: A flaw was found in grub2

osv·2025-02-19·CVSS 6.4

CVE-2025-0677 [MEDIUM] CVE-2025-0677: A flaw was found in grub2 A flaw was found in grub2. When performing a symlink lookup, the grub's UFS module checks the inode's data size to allocate the internal buffer to read the file content, however, it fails to check if the symlink data size has overflown. When this occurs, grub_malloc() may be called with a smaller value than needed. When further reading the data from the disk into the buffer, the grub_ufs_lookup_symlink() function will write past the end of the allocated size. An attack can leverage this by crafting a malicious filesystem, and as a result, it will corrupt data stored in the heap, allowing for arbitrary code execution used to by-pass secure boot mechanisms.

CVE-2025-0677: A flaw was found in grub2. When performing a symlink lookup, the grub's UFS module checks the inode's data size to allocate the internal buffer to read the…

Affected

CVSS provenance