{"id":2976,"date":"2025-04-01T10:04:17","date_gmt":"2025-04-01T10:04:17","guid":{"rendered":"https:\/\/serisec.com\/index.php\/2025\/04\/01\/microsoft-uncovers-several-vulnerabilities-in-grub2-u-boot-barebox-bootloaders-using-copilot\/"},"modified":"2025-04-01T10:04:17","modified_gmt":"2025-04-01T10:04:17","slug":"microsoft-uncovers-several-vulnerabilities-in-grub2-u-boot-barebox-bootloaders-using-copilot","status":"publish","type":"post","link":"https:\/\/serisec.com\/index.php\/2025\/04\/01\/microsoft-uncovers-several-vulnerabilities-in-grub2-u-boot-barebox-bootloaders-using-copilot\/","title":{"rendered":"Microsoft Uncovers Several Vulnerabilities in GRUB2, U-Boot, Barebox Bootloaders Using Copilot"},"content":{"rendered":"

Microsoft Uncovers Several Vulnerabilities in GRUB2, U-Boot, Barebox Bootloaders Using Copilot
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Microsoft has discovered multiple critical vulnerabilities affecting widely used bootloaders including GRUB2, U-Boot, and Barebox.<\/p>\n

These security flaws potentially expose systems to sophisticated boot-level attacks that could compromise devices before operating systems even initialize, allowing attackers to gain persistent and nearly undetectable control over affected systems.<\/p>\n

The vulnerabilities impact thousands of Linux systems and embedded devices that rely on these open-source bootloaders to initialize hardware and load operating systems.<\/p>\n

GRUB2 (Grand Unified Bootloader version 2) is particularly concerning given its widespread adoption across enterprise Linux distributions and some secure boot implementations.<\/p>\n

U-Boot and Barebox vulnerabilities affect numerous embedded systems, IoT devices<\/a>, and network appliances, creating a vast attack surface across industries.<\/p>\n

Microsoft researchers noted<\/a> these flaws during a proactive security review using their AI-powered Copilot tool to analyze bootloader codebases.<\/p>\n

The company\u2019s security team discovered that specific memory handling functions within these bootloaders fail to properly validate input sizes, potentially allowing attackers to execute arbitrary code during the boot process.<\/p>\n

These vulnerabilities exist in the secure boot<\/a> verification chain, potentially undermining the foundational security these systems are built upon.<\/p>\n

Vulnerabilities<\/strong><\/strong><\/h2>\n

The most severe vulnerability, tracked as CVE-2025-21XX, affects GRUB2\u2019s memory allocation functions when parsing configuration files.<\/p>\n

Here below we have mentioned all the vulnerabilities:-<\/p>\n

\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
Bootloader<\/th>\nVulnerability<\/th>\n<\/tr>\n<\/thead>\n
GRUB2<\/td>\nCVE-2024-56737<\/td>\n<\/tr>\n
GRUB2<\/td>\nCVE-2024-56738<\/td>\n<\/tr>\n
GRUB2<\/td>\nCVE-2025-0677<\/td>\n<\/tr>\n
GRUB2<\/td>\nCVE-2025-0678<\/td>\n<\/tr>\n
GRUB2<\/td>\nCVE-2025-0684<\/td>\n<\/tr>\n
GRUB2<\/td>\nCVE-2025-0685<\/td>\n<\/tr>\n
GRUB2<\/td>\nCVE-2025-0686<\/td>\n<\/tr>\n
GRUB2<\/td>\nCVE-2025-0689<\/td>\n<\/tr>\n
GRUB2<\/td>\nCVE-2025-0690<\/td>\n<\/tr>\n
GRUB2<\/td>\nCVE-2025-1118<\/td>\n<\/tr>\n
GRUB2<\/td>\nCVE-2025-1125<\/td>\n<\/tr>\n
U-boot<\/td>\nCVE-2025-26726<\/td>\n<\/tr>\n
U-boot<\/td>\nCVE-2025-26727<\/td>\n<\/tr>\n
U-boot<\/td>\nCVE-2025-26728<\/td>\n<\/tr>\n
U-boot<\/td>\nCVE-2025-26729<\/td>\n<\/tr>\n
Barebox<\/td>\nCVE-2025-26721<\/td>\n<\/tr>\n
Barebox<\/td>\nCVE-2025-26722<\/td>\n<\/tr>\n
Barebox<\/td>\nCVE-2025-26723<\/td>\n<\/tr>\n
Barebox<\/td>\nCVE-2025-26724<\/td>\n<\/tr>\n
Barebox<\/td>\nCVE-2025-26725<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/figure>\n

An attacker with physical access or administrative privileges could exploit this flaw to bypass secure boot mechanisms and execute malicious code that persists across system reboots and reinstallations.<\/p>\n

One particularly concerning vulnerability involves improper boundary checking in GRUB2\u2019s parsing function, as demonstrated in this vulnerable code segment:-<\/p>\n

grub_err_t grub_parser_execute(char *script)\n{\n  grub_parser_t parser = grub_parser_get_current();\n  return parser->parse_line(script, read_hook); \/\/ No proper input validation\n}<\/code><\/pre>\n
The technical analysis reveals that attackers could craft specially formatted configuration entries that trigger buffer overflow conditions, allowing arbitrary code execution during boot.<\/p>\n
This exploitation technique bypasses traditional security controls by gaining execution before the operating system security features activate.<\/p>\n
Microsoft\u2019s discovery underscores the critical importance of securing the boot process as a fundamental layer of defense.<\/p>\n
System administrators are advised to apply emergency patches that bootloader<\/a> maintainers have released in response to Microsoft\u2019s responsible disclosure.<\/p>\n
For systems that cannot be immediately updated, Microsoft recommends implementing physical security measures<\/a> and restricting administrative access to mitigate the risk of exploitation.<\/p>\n
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GRUB2 Bootloader Vulnerability Exploitation Chain (Source \u2013 Microsoft)<\/figcaption><\/figure>\n<\/div>\n
This discovery highlights the growing role of AI-assisted cybersecurity research in identifying complex vulnerabilities in critical infrastructure components that might otherwise remain undiscovered until exploited in the wild.<\/p>\n
Are You from SOC\/DFIR Team? - Try Free\u00a0Malware Research\u00a0with ANY.RUN -\u00a0Start Now<\/a><\/code><\/strong><\/p>\n
The post Microsoft Uncovers Several Vulnerabilities in GRUB2, U-Boot, Barebox Bootloaders Using Copilot<\/a> appeared first on Cyber Security News<\/a>.<\/p>\n<\/div>\n
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\n    Tushar Subhra Dutta
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Microsoft Uncovers Several Vulnerabilities in GRUB2, U-Boot, Barebox Bootloaders Using Copilot Microsoft has discovered multiple critical vulnerabilities affecting widely used bootloaders including GRUB2, U-Boot, and Barebox. These security flaws potentially expose systems to sophisticated boot-level attacks that could compromise devices before operating systems even initialize, allowing attackers to gain persistent and nearly undetectable control over […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[63,649,131],"tags":[130],"class_list":["post-2976","post","type-post","status-publish","format-standard","hentry","category-cyber-security-news","category-threats","category-vulnerability","tag-cyber-security-news"],"_links":{"self":[{"href":"https:\/\/serisec.com\/index.php\/wp-json\/wp\/v2\/posts\/2976"}],"collection":[{"href":"https:\/\/serisec.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/serisec.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/serisec.com\/index.php\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/serisec.com\/index.php\/wp-json\/wp\/v2\/comments?post=2976"}],"version-history":[{"count":0,"href":"https:\/\/serisec.com\/index.php\/wp-json\/wp\/v2\/posts\/2976\/revisions"}],"wp:attachment":[{"href":"https:\/\/serisec.com\/index.php\/wp-json\/wp\/v2\/media?parent=2976"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/serisec.com\/index.php\/wp-json\/wp\/v2\/categories?post=2976"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/serisec.com\/index.php\/wp-json\/wp\/v2\/tags?post=2976"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}