CVE-2019-13106 Denx CVE debrief

Who should care

Embedded and IoT device vendors, firmware engineers, bootloader maintainers, and distro or platform teams that ship U-Boot-based systems should pay attention. Teams that boot from removable media, network-delivered images, or other untrusted storage are especially relevant.

Technical summary

The issue is a memory-safety bug in U-Boot’s ext4 reader. When processing a specially crafted ext4 filesystem, memset() can clear beyond the intended stack buffer boundary, producing a stack-based buffer overflow. The published description indicates likely code execution, and NVD maps the weakness to CWE-787.

Defensive priority

High. The attack vector is local and requires user interaction, but the affected component is a bootloader, so compromise can occur very early in system startup and may have outsized security impact.

Recommended defensive actions

• Inventory all products and images that use U-Boot and check the exact version in use.
• Upgrade to a non-vulnerable U-Boot release using vendor or upstream guidance.
• Review firmware update and boot media workflows for exposure to untrusted ext4 images.
• Prioritize systems that parse removable, externally supplied, or network-fetched boot media.
• Use trusted, controlled boot assets and validate vendor advisories before deployment.
• Track downstream advisories for platform-specific backports and fix status.

Evidence notes

The debrief is based on the supplied NVD record and linked references. The CVE description states that U-Boot versions 2016.09 through 2019.07-rc4 can overflow a stack buffer while reading a crafted ext4 filesystem. The NVD CPE criteria also mark U-Boot 2019.07 and 2019.07-rc1 through rc4 as vulnerable, so the exact affected range should be checked against the specific build or backport status. References include an upstream U-Boot mailing list patch and downstream advisories from openSUSE and Siemens.

Official resources