CVE-2025-70100

medium

Description

A divide-by-zero vulnerability in the ext4_block_set_lb_size function in src/ext4_blockdev.c of the lwext4 1.0.0 library allows attackers to cause a denial of service by providing a malformed ext4 filesystem image that results in a zero logical block size. The vulnerability is triggered during mount or image processing and leads to a Floating-Point Exception (FPE) under sanitizers or a runtime crash in standard builds due to missing validation of lb_size.

References

https://infosec.exchange/@sigdevel/116668952003072580

https://github.com/sigdevel/pocs/blob/main/res/lwext4/2/sig8_2_lwext4_ext4_blockdev_c_127

https://github.com/gkostka/lwext4/issues/90

Details

Source: Mitre, NVD

Published: 2026-06-03

Updated: 2026-06-03

Risk Information

CVSS v2

Base Score: 4.3

Vector: CVSS2#AV:N/AC:M/Au:N/C:N/I:N/A:P

Severity: Medium

CVSS v3

Base Score: 5.5

Vector: CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

Severity: Medium