CVE-2025-0685 Grub2: jfs: integer overflow when handling symlinks may lead to heap based out-of-bounds write when reading data
A malicious JFS filesystem can trigger an integer overflow in GRUB2, leading to heap corruption and arbitrary code execution that bypasses Secure Boot.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-0685?
CVE-2025-0685 is a medium-severity vulnerability in Red Hat Enterprise Linux 10, published on 3 Mar 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
A flaw was found in grub2. When reading data from a jfs filesystem, grub's jfs filesystem module uses user-controlled parameters from the filesystem geometry to determine the internal buffer size, however, it improperly checks for integer overflows. A maliciouly 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_jfs_lookup_symlink() function will write past the internal buffer length during grub_jfs_read_file(). This issue can be leveraged to corrupt grub's internal critical data and may result in arbitrary code execution, by-passing secure boot protections.
Weakness: CWE-787
Which versions are affected by CVE-2025-0685?
It affects 1 product.
Products include Gnu Grub2.
How do I fix CVE-2025-0685?
Apply the vendor's patch.
Is CVE-2025-0685 being exploited?
There is no known exploitation of CVE-2025-0685 in the wild and no public exploit code.
Other vulnerabilities in Red Hat Enterprise Linux 10
- CVE-2024-56737 Memory corruption in GRUB2
- CVE-2022-28733 Integer underflow in grub_net_recv_ip4_packets
- CVE-2022-28734 Out-of-bounds write when handling split HTTP headers
- CVE-2025-61662 Grub2: missing unregister call for gettext command may lead to use-after-free
- CVE-2024-45782 Grub2: fs/hfs: strcpy() using the volume name (fs/hfs.c:382)
Sources
Also known as AZL-57681, AZL-57709, BELL-CVE-2025-0685, DEBIAN-CVE-2025-0685, GHSA-37r5-v3hg-cg4r, UBUNTU-CVE-2025-0685.