CVE-2025-21687 | vfio/platform: check the bounds of read/write syscalls

In the Linux kernel, the following vulnerability has been resolved: vfio/platform: check the bounds of read/write syscalls count and offset are passed from user space and not checked, only offset is capped to 40 bits, which can be used to read/write out of bounds of the device.

Published: 2025-02-10 Last update: 2025-11-03 Assigner: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2025-21687 is rated Low Risk (35.5/100): CVSS High severity, with low exploitation likelihood (EPSS 0.22%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2025-21687

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.04% 0.22% +0.17%
2 2025-11-21 0.08% 0.04% -0.04%
3 2025-11-18 — 0.08% —

Full EPSS history (4 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-21687

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.8 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 5.9 [email protected]

Weakness enumeration for CVE-2025-21687

OS Trackers for CVE-2025-21687

vendor priority summary link
debian not yet assigned CVE-2025-21687 not yet assigned priority: Debian including 2 source packages (linux, linux-6.1), 6 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 6. https://security-tracker.debian.org/tracker/CVE-2025-21687
redhat medium — https://access.redhat.com/security/cve/CVE-2025-21687
suse high CVE-2025-21687 severity important: SUSE including 418 source package names (2.1.3-6.11:kernel-default-6.4.0-28.1, 2.1.3-6.12:kernel-default-base-6.4.0-28.1.21.6, …), 809 product×package rows across 145 product lines (Container suse/sl-micro/6.0/base-os-container, Container suse/sl-micro/6.0/kvm-os-container, … (145 product lines)): Fixed 362, Known Affected 231, Known Not Affected 216. https://www.suse.com/security/cve/CVE-2025-21687/
ubuntu medium CVE-2025-21687 medium priority: Ubuntu including 158 source packages (linux, linux-allwinner-5.19, …), 1551 status rows across 10 suites (bionic, focal, jammy, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 1145, ignored 168, released 146, needed 53, not-affected 39. https://ubuntu.com/security/CVE-2025-21687

Affected software / configurations for CVE-2025-21687

Vendor Product Version Raw CPE
linux linux_kernel >= 4.1, < 5.4.290 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 5.5, < 5.10.234 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 5.11, < 5.15.178 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 5.16, < 6.1.128 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.2, < 6.6.75 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.7, < 6.12.12 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel 6.13 cpe:2.3:o:linux:linux_kernel:6.13:-:*:*:*:*:*:*
linux linux_kernel 6.13 cpe:2.3:o:linux:linux_kernel:6.13:rc1:*:*:*:*:*:*
linux linux_kernel 6.13 cpe:2.3:o:linux:linux_kernel:6.13:rc2:*:*:*:*:*:*
linux linux_kernel 6.13 cpe:2.3:o:linux:linux_kernel:6.13:rc3:*:*:*:*:*:*
linux linux_kernel 6.13 cpe:2.3:o:linux:linux_kernel:6.13:rc4:*:*:*:*:*:*
linux linux_kernel 6.13 cpe:2.3:o:linux:linux_kernel:6.13:rc5:*:*:*:*:*:*
linux linux_kernel 6.13 cpe:2.3:o:linux:linux_kernel:6.13:rc6:*:*:*:*:*:*
linux linux_kernel 6.13 cpe:2.3:o:linux:linux_kernel:6.13:rc7:*:*:*:*:*:*

References for CVE-2025-21687

URL Tags
https://git.kernel.org/stable/c/1485932496a1b025235af8aa1e21988d6b7ccd54 Patch
https://git.kernel.org/stable/c/665cfd1083866f87301bbd232cb8ba48dcf4acce Patch
https://git.kernel.org/stable/c/6bcb8a5b70b80143db9bf12dfa7d53636f824d53 Patch
https://git.kernel.org/stable/c/92340e6c5122d823ad064984ef7513eba9204048 Patch
https://git.kernel.org/stable/c/9377cdc118cf327248f1a9dde7b87de067681dc9
https://git.kernel.org/stable/c/a20fcaa230f7472456d12cf761ed13938e320ac3 Patch
https://git.kernel.org/stable/c/c981c32c38af80737a2fedc16e270546d139ccdd Patch
https://git.kernel.org/stable/c/ce9ff21ea89d191e477a02ad7eabf4f996b80a69 Patch
https://git.kernel.org/stable/c/d19a8650fd3d7aed8d1af1d9a77f979a8430eba1 Patch
https://git.kernel.org/stable/c/ed81d82bb6e9df3a137f2c343ed689e6c68268ef
https://git.kernel.org/stable/c/f21636f24b6786c8b13f1af4319fa75ffcf17f38 Patch
https://git.kernel.org/stable/c/f65ce06387f8c1fb54bd59e18a8428248ec68eaf
https://lists.debian.org/debian-lts-announce/2025/03/msg00001.html
https://lists.debian.org/debian-lts-announce/2025/03/msg00002.html
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