{"id":"CVE-2024-21963","kind":"vulnerability","aliases":["CVE-2024-21963"],"related":[],"title":"IOMMU out-of-bounds read lets a malicious guest crash the host","description":"An out-of-bounds read vulnerability in the IOMMU could allow a malicious guest to corrupt hypervisor (HV) pages and potentially cause a host crash leading to loss of availability.","summary":"An out-of-bounds read in the IOMMU lets a malicious guest virtual machine corrupt hypervisor memory pages. The result can be a host crash, which takes down availability for everything running on that machine.","severity":"medium","cvss":6.0,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["hypervisor","infrastructure","iommu","virtualization"],"not_affected_if":["no-untrusted-guests"],"how_to_check":null,"fix":null,"status":"open","published_at":"2026-11-12T20:18:09+00:00","first_seen_at":"2026-11-12T20:40:22+00:00","triaged_at":"2026-11-12T20:42:20+00:00","updated_at":"2026-11-12T20:42:20+00:00","category":"infrastructure","confidence":0.5,"triage":{"at":"2026-11-12T20:42:20Z","model":"claude-haiku-5-5","output":{"fix":"unknown","reach":"local","title":"IOMMU out-of-bounds read lets a malicious guest crash the host","impact":"medium","summary":"An out-of-bounds read in the IOMMU lets a malicious guest virtual machine corrupt hypervisor memory pages. The result can be a host crash, which takes down availability for everything running on that machine.","audience":"businesses","category":"infrastructure","nicknames":[],"who_cares":["hypervisor","virtualization","iommu"],"confidence":0.5,"fix_status":"unknown","needs_auth":"yes","worst_case":"malicious guest crashes host, losing availability of hosted systems","analyst_note":"Identify the affected hypervisor products and fixed versions from the vendor advisory linked from NVD (the Xen or AMD advisory for this IOMMU flaw).","how_to_check":"unknown","plain_action":"","product_name":"","needs_analyst":true,"not_affected_if":["no-untrusted-guests"],"who_is_affected":"Affects hosts that run virtual machines and use the IOMMU for device passthrough, where a guest can act maliciously. The sources do not name the affected hypervisor products or versions. Systems that run no hypervisor or no untrusted guests are unlikely to be exposed.","user_interaction":"no","product_ecosystem":"","needs_special_setup":"unknown","severity_if_unknown":"medium"},"cost_usd":0.00069,"input_tokens":4529,"output_tokens":474,"severity_before":"medium"},"analyst_status":null,"analyst_note":null,"search":"'-2024':15A,18A '-21963':16A,19A 'allow':71C 'avail':53B,90C 'bound':5A,28B,64C 'caus':82C 'corrupt':39B,76C 'could':70C 'crash':11A,49B,85C 'cve':14A,17A 'everyth':55B 'guest':10A,36B,74C 'host':13A,48B,84C 'hv':78C 'hypervisor':20B,40B,77C 'infrastructur':21B 'iommu':1A,22B,32B,69C 'lead':86C 'let':7A,33B 'loss':88C 'machin':38B,59B 'malici':9A,35B,73C 'memori':41B 'out-of-bound':2A,25B,61C 'page':42B,79C 'potenti':81C 'read':6A,29B,65C 'result':44B 'run':56B 'take':51B 'virtual':23B,37B 'vulner':66C","nicknames":[],"mitigations":[],"who_affected":"Affects hosts that run virtual machines and use the IOMMU for device passthrough, where a guest can act maliciously. The sources do not name the affected hypervisor products or versions. Systems that run no hypervisor or no untrusted guests are unlikely to be exposed.","tier":"C","verified":{},"analyst_revisit_at":null,"fix_status":"none","audience":"businesses","plain_action":null,"pkeys":[],"ptokens":[],"labels":["hypervisor","infrastructure","iommu","medium","virtualization"],"campaign_type":null,"search_a":"'-2024':15A,18A '-21963':16A,19A 'bound':5A 'crash':11A 'cve':14A,17A 'guest':10A 'host':13A 'iommu':1A 'let':7A 'malici':9A 'out-of-bound':2A 'read':6A","search_b":"'avail':53B 'bound':28B 'corrupt':39B 'crash':49B 'everyth':55B 'guest':36B 'host':48B 'hypervisor':20B,40B 'infrastructur':21B 'iommu':22B,32B 'let':33B 'machin':38B,59B 'malici':35B 'memori':41B 'out-of-bound':25B 'page':42B 'read':29B 'result':44B 'run':56B 'take':51B 'virtual':23B,37B","search_c":"'allow':71C 'avail':90C 'bound':64C 'caus':82C 'corrupt':76C 'could':70C 'crash':85C 'guest':74C 'host':84C 'hv':78C 'hypervisor':77C 'iommu':69C 'lead':86C 'loss':88C 'malici':73C 'out-of-bound':61C 'page':79C 'potenti':81C 'read':65C 'vulner':66C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-11-12T20:18:09+00:00","kev":null,"cvss_vector":"CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","cvss_by":"psirt@amd.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2024-21963","url":"https://nvd.nist.gov/vuln/detail/CVE-2024-21963","severity":null,"published_at":"2026-11-12T20:18:09+00:00","modified_at":"2026-11-12T20:18:09+00:00","first_seen_at":"2026-11-12T20:40:22+00:00","fetched_at":"2026-11-12T20:40:22+00:00","note":null}],"documents":[],"disclosures":[],"exploit_sources":[],"notice":"Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai"}