CVE-2025-0686 — 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	<= 2.12	—
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	—	—

Microsoft

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

vendor_msrc·2025-03-11·CVSS 6.4

CVE-2025-0686 [MEDIUM] CWE-787 Grub2: romfs: integer overflow when handling symlinks may lead to heap based out-of-bounds write when reading dat Grub2: romfs: integer overflow when handling symlinks may lead to heap based out-of-bounds write when reading dat 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

Red Hat

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

vendor_redhat·2025-02-18·CVSS 6.4

CVE-2025-0686 [MEDIUM] CWE-787 grub2: romfs: Integer overflow when handling symlinks may lead to heap based out-of-bounds write when reading dat grub2: romfs: Integer overflow when handling symlinks may lead to heap based out-of-bounds write when reading dat A flaw was found in grub2. When performing a symlink lookup from a romfs filesystem, grub's romfs filesystem module uses user-controlled parameters from the filesystem geometry to determine the internal buffer size, however, it improperly checks for integer overflows. A maliciously crafted filesystem may lead some of those buffer size calculations to overflow, causing it to perform a grub_malloc() operation with a smaller size than expected. As a result, the grub_romfs_read_symlink() may cause out-of-bounds writes when the calling grub_disk_read() function. This issue may be leveraged to corrupt grub's internal critical data and can result in arbitrary code execution by-passin

Debian

CVE-2025-0686: grub2 - A flaw was found in grub2. When performing a symlink lookup from a romfs filesys...

vendor_debian·2025·CVSS 6.4

CVE-2025-0686 [MEDIUM] CVE-2025-0686: grub2 - A flaw was found in grub2. When performing a symlink lookup from a romfs filesys... A flaw was found in grub2. When performing a symlink lookup from a romfs filesystem, grub's romfs filesystem module uses user-controlled parameters from the filesystem geometry to determine the internal buffer size, however, it improperly checks for integer overflows. A maliciously crafted filesystem may lead some of those buffer size calculations to overflow, causing it to perform a grub_malloc() operation with a smaller size than expected. As a result, the grub_romfs_read_symlink() may cause out-of-bounds writes when the calling grub_disk_read() function. This issue may be leveraged to corrupt grub's internal critical data and can result in arbitrary code execution by-passing secure boot protections. Scope: local bookworm: open bullseye: open forky: resolved (fixed in 2.12-6) sid: resolv

GHSA

GHSA-5pg5-wv5r-mmj7: A flaw was found in grub2

ghsa_unreviewed·2025-03-03

CVE-2025-0686 [MEDIUM] CWE-787 GHSA-5pg5-wv5r-mmj7: A flaw was found in grub2 A flaw was found in grub2. When performing a symlink lookup from a romfs filesystem, grub's romfs filesystem module uses user-controlled parameters from the filesystem geometry to determine the internal buffer size, however, it improperly checks for integer overflows. A maliciously crafted filesystem may lead some of those buffer size calculations to overflow, causing it to perform a grub_malloc() operation with a smaller size than expected. As a result, the grub_romfs_read_symlink() may cause out-of-bounds writes when the calling grub_disk_read() function. This issue may be leveraged to corrupt grub's internal critical data and can result in arbitrary code execution by-passing secure boot protections.

OSV

CVE-2025-0686: A flaw was found in grub2

osv·2025-03-03·CVSS 6.4

CVE-2025-0686 [MEDIUM] CVE-2025-0686: A flaw was found in grub2 A flaw was found in grub2. When performing a symlink lookup from a romfs filesystem, grub's romfs filesystem module uses user-controlled parameters from the filesystem geometry to determine the internal buffer size, however, it improperly checks for integer overflows. A maliciously crafted filesystem may lead some of those buffer size calculations to overflow, causing it to perform a grub_malloc() operation with a smaller size than expected. As a result, the grub_romfs_read_symlink() may cause out-of-bounds writes when the calling grub_disk_read() function. This issue may be leveraged to corrupt grub's internal critical data and can result in arbitrary code execution by-passing secure boot protections.

CVE-2025-0686: A flaw was found in grub2. When performing a symlink lookup from a romfs filesystem, grub's romfs filesystem module uses user-controlled parameters from the…

Affected

CVSS provenance