medium5.5
CVE-2025-70100
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 …
Impact
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.
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Gkostka | Lwext4 | Version 1.0.0 |
Weakness classification
References
- NVD record
- CVE.org record
- https://github.com/gkostka/lwext4/issues/90
- https://github.com/sigdevel/pocs/blob/main/res/lwext4/2/sig8_2_lwext4_ext4_blockdev_c_127
- https://infosec.exchange/@sigdevel/116668952003072580
- http://www.openwall.com/lists/oss-security/2026/06/29/5
- https://github.com/gkostka/lwext4/issues/90