CVE-2025-70100
MediumCVSS 5.5Exploitation Probability (EPSS)
Low risk5th percentile - higher than 5% of all known CVEs
Summary
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.
Risk Assessment
An attacker can crash an application using lwext4 during mount or image processing, leading to service disruption.
Recommendation
Update the lwext4 library to a version that includes a fix validating the logical block size.
Other vulnerabilities in lwext4
See all- CVE-2025-70101Medium
An out-of-bounds read vulnerability exists in the ext4_ext_binsearch_idx function in src/ext4_extent.c of the lwext4 1.0.0 library. Insufficient validation of extent header fields before performing a binary search can lead to invalid pointer calculations and out-of-bounds memory read during extent tree traversal.
- CVE-2025-70099High
lwext4 1.0.0 has a NULL pointer dereference in the ext4_dir_en_get_name_len function in include/ext4_dir.h. An attacker can supply a specially crafted EXT4 filesystem image with malformed directory entries, causing a segmentation fault (DoS).
Original NVD description (English source)
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.