{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata — refreshed continuously.","feed_url":"https://feed.craftedsignal.io/tags/grub2/","home_page_url":"https://feed.craftedsignal.io/","items":[{"_cs_actors":[],"_cs_cves":[],"_cs_exploited":false,"_cs_products":[],"_cs_severities":["high"],"_cs_tags":["bootloader","grub2","vulnerability","denial-of-service","arbitrary-code-execution"],"_cs_type":"advisory","_cs_vendors":[],"content_html":"\u003cp\u003eThe GRUB2 bootloader, a critical component responsible for initiating the operating system startup process, contains multiple vulnerabilities. Successful exploitation of these vulnerabilities allows an attacker to execute arbitrary code within the context of the bootloader or cause a denial-of-service (DoS) condition, preventing the system from booting correctly. These vulnerabilities impact any system using a vulnerable GRUB2 version. While the specific vulnerable versions aren\u0026rsquo;t mentioned, it\u0026rsquo;s important for defenders to assess and patch systems using GRUB2. The impact of successful exploitation ranges from gaining complete control over the system\u0026rsquo;s boot process to rendering the system unusable.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eAttacker gains initial access to the system (physical access or remote access via another vulnerability).\u003c/li\u003e\n\u003cli\u003eAttacker modifies the grub.cfg file, the main configuration file for GRUB2, either directly or indirectly through other system vulnerabilities.\u003c/li\u003e\n\u003cli\u003eThe modified grub.cfg introduces malicious code or configurations exploiting a GRUB2 vulnerability.\u003c/li\u003e\n\u003cli\u003eThe system is rebooted, triggering the GRUB2 bootloader.\u003c/li\u003e\n\u003cli\u003eGRUB2 parses the malicious configuration in grub.cfg.\u003c/li\u003e\n\u003cli\u003eDue to the vulnerability, the malicious code is executed with elevated privileges, allowing arbitrary code execution.\u003c/li\u003e\n\u003cli\u003eAlternatively, the malicious configuration triggers a denial-of-service condition within GRUB2, causing a system crash or preventing the boot process from completing.\u003c/li\u003e\n\u003cli\u003eThe attacker achieves arbitrary code execution at the bootloader level or renders the system unusable.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation of these vulnerabilities can lead to complete system compromise, as the attacker gains control over the boot process. This can allow for the installation of rootkits, bypass of security measures, and exfiltration of sensitive data. Furthermore, a denial-of-service attack can render systems unusable, leading to data loss and business disruption. The lack of specific victim data prevents quantification, but the potential impact is significant for any system relying on GRUB2.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eImplement file integrity monitoring on \u003ccode\u003e/boot/grub/grub.cfg\u003c/code\u003e and other GRUB2 configuration files to detect unauthorized modifications (reference: Attack Chain step 2 and file_event log source).\u003c/li\u003e\n\u003cli\u003eDeploy the provided Sigma rules to detect suspicious process executions that could indicate attempts to modify GRUB2 configuration files (reference: rules section).\u003c/li\u003e\n\u003cli\u003eRegularly audit and update GRUB2 installations to the latest patched version to mitigate known vulnerabilities (reference: Overview section).\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2026-03-25T10:22:08Z","date_published":"2026-03-25T10:22:08Z","id":"/briefs/2024-05-grub-vulns/","summary":"Multiple vulnerabilities in the Grub bootloader allow attackers to execute arbitrary code and cause denial-of-service conditions.","title":"Multiple Vulnerabilities in Grub Bootloader","url":"https://feed.craftedsignal.io/briefs/2024-05-grub-vulns/"}],"language":"en","title":"CraftedSignal Threat Feed — Grub2","version":"https://jsonfeed.org/version/1.1"}