CVE-2025-70100
Gkostka Lwext4 1.0.0
Raw vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:HCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2025-70100 is a medium-severity Divide By Zero (CWE-369) vulnerability in Gkostka Lwext4. Its CVSS base score is 5.5 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Endpoint Denial of Service (T1499); ranked at the 6th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SA-8 (Security and Privacy Engineering Principles) — see the control section below for these in your framework.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-210054
Vulnerability Data
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…
more
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.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Developer testing and evaluation (including static/dynamic analysis) finds divide-by-zero conditions after they have been coded.
Security engineering principles can require safe-arithmetic constructs or explicit guards that keep division operands nonzero.
Validating numeric inputs before use as divisors structurally blocks zero values from reaching division operations.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure SDLC practices directly include code analysis, input validation, and testing that prevent divide-by-zero errors.
Vulnerability identification processes can discover divide-by-zero flaws via static analysis or testing.
Routine patching and replacement can remediate divide-by-zero bugs present in deployed software.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing in development can detect divide-by-zero conditions before release.
Secure development lifecycle includes input validation and error-handling practices that can prevent divide-by-zero faults.
Application security requirements can mandate checks for zero denominators and safe arithmetic handling.
Secure architecture principles encourage defensive coding patterns that avoid arithmetic exceptions.
Secure coding standards directly require validation to prevent divide-by-zero and similar runtime faults.