CVE-2025-70101 — MEDIUM (6.5)

Vulnerability Description

An out-of-bounds read in the ext4_ext_binsearch_idx function in src/ext4_extent.c of the lwext4 1.0.0 library allows attackers to cause a denial of service by supplying a specially crafted ext4 filesystem image. The vulnerability occurs due to insufficient validation of extent header fields before performing a binary search over extent index entries, which can result in invalid pointer calculations and an out-of-bounds memory read during extent tree traversal.

CVSS Score

6.5

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

REQUIRED

Scope

UNCHANGED

Confidentiality

HIGH

Integrity

NONE

Availability

NONE

Affected Products

Vendor	Product	Versions
Gkostka	Lwext4	1.0.0

Related Weaknesses (CWE)

CWE-125

References

https://github.com/gkostka/lwext4/issues/91ExploitIssue TrackingPatch
https://github.com/sigdevel/pocs/blob/main/res/lwext4/3/sig11_lwext4_ext4_extentExploit
https://infosec.exchange/@sigdevel/116668958927817708ExploitPatchThird Party Advisory
http://www.openwall.com/lists/oss-security/2026/06/29/6
https://github.com/gkostka/lwext4/issues/91ExploitIssue TrackingPatch

FAQ

What is CVE-2025-70101?

CVE-2025-70101 is a vulnerability with a CVSS score of 6.5 (MEDIUM). An out-of-bounds read in the ext4_ext_binsearch_idx function in src/ext4_extent.c of the lwext4 1.0.0 library allows attackers to cause a denial of service by supplying a specially crafted ext4 filesy...

How severe is CVE-2025-70101?

CVE-2025-70101 has been rated MEDIUM with a CVSS base score of 6.5/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2025-70101?

Check the references section above for vendor advisories and patch information. Affected products include: Gkostka Lwext4.