What’s Vulnerable › Vulnerabilities

CVE-2022-34303

• Severity: medium (CVSS 6.7 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.9% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2022-08-26 · updated 2026-06-17

Description

A flaw was found in Eurosoft bootloaders before 2022-06-01. An attacker may use this bootloader to bypass or tamper with Secure Boot protections. In order to load and execute arbitrary code in the pre-boot stage, an attacker simply needs to replace the existing signed bootloader currently in use with this bootloader. Access to the EFI System Partition is required for booting using external media.

Affected products

• Eurosoft-Uk Uefi Bootloader: before 2022-06-01 — fixed in 2022-06-01
• Microsoft Windows 10 Version 1607: 20h2, 21h1, 21h2, 1607, 1809
• Microsoft Windows 11 version 21H2: all versions
• Microsoft Windows 8.1: all versions
• Microsoft Windows RT 8.1: all versions
• Microsoft Windows Server 2012: r2
• Microsoft Windows Server 2016: 20h2
• Microsoft Windows Server 2019: all versions
• Microsoft Windows Server 2022: all versions
• Red Hat Enterprise Linux: 7.0, 8.0, 9.0

How to fix

Upgrade to a fixed version: Eurosoft-Uk Uefi Bootloader 2022-06-01. Check the vendor advisory for mitigations.

References

• https://edk2-docs.gitbook.io/understanding-the-uefi-secure-boot-chain/secure_boot_chain_in_uefi/uefi_secure_boot
• https://www.intel.com/content/www/us/en/security-center/advisory/intel-sa-01001.html
• https://www.kb.cert.org/vuls/id/309662
• https://edk2-docs.gitbook.io/understanding-the-uefi-secure-boot-chain/secure_boot_chain_in_uefi/uefi_secure_boot
• https://www.intel.com/content/www/us/en/security-center/advisory/intel-sa-01001.html
• https://www.kb.cert.org/vuls/id/309662

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