CVE-2025-21993
In the Linux kernel, the following vulnerability has been resolved: iscsi_ibft: Fix UBSAN shift-out-of-bounds warning in ibft_attr_show_nic() When performing an iSCSI boot using IPv6, iscsistart still reads the /sys/firmware/ibft/ethernetX/subnet-mask…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.21%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
In the Linux kernel, the following vulnerability has been resolved: iscsi_ibft: Fix UBSAN shift-out-of-bounds warning in ibft_attr_show_nic() When performing an iSCSI boot using IPv6, iscsistart still reads the /sys/firmware/ibft/ethernetX/subnet-mask entry. Since the IPv6 prefix length is 64, this causes the shift exponent to become negative, triggering a UBSAN warning. As the concept of a subnet mask does not apply to IPv6, the value is set to ~0 to suppress the warning message.
- CVSS 3.1
- 7.1 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
- EPSS
- 0.21% probability · 12th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-125
- Affected
- linux/linux kernel
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/07e0d99a2f701123ad3104c0f1a1e66bce74d6e5Patch
- https://git.kernel.org/stable/c/2d1eef248107bdf3d5a69d0fde04c30a79a7bf5dPatch
- https://git.kernel.org/stable/c/9bfa80c8aa4e06dff55a953c3fffbfc68a3a3b1cPatch
- https://git.kernel.org/stable/c/a858cd58dea06cf85b142673deea8c5d87f11e70Patch
- https://git.kernel.org/stable/c/b253660fac5e0e9080d2c95e3a029e1898d49afbPatch
- https://git.kernel.org/stable/c/b388e185bfad32bfed6a97a6817f74ca00a4318fPatch
- https://git.kernel.org/stable/c/c1c6e527470e5eab0b2d57bd073530fbace39eabPatch
- https://git.kernel.org/stable/c/f763c82db8166e28f45b7cc4a5398a7859665940Patch
- https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html
- https://lists.debian.org/debian-lts-announce/2025/05/msg00045.html
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.