{"id":"CVE-2020-9818","kind":"vulnerability","aliases":["CVE-2020-9818"],"related":[],"title":"Apple iOS, iPadOS, and watchOS: Apple iOS, iPadOS, and watchOS Out-of-Bounds Write Vulnerability","description":"An out-of-bounds write issue was addressed with improved bounds checking. This issue is fixed in iOS 13.5 and iPadOS 13.5, iOS 12.4.7, watchOS 6.2.5. Processing a maliciously crafted mail message may lead to unexpected memory modification or application termination.","summary":"Apple's iOS, iPadOS and watchOS Mail app has an out-of-bounds write flaw triggered when it processes a specially crafted email. An attacker can corrupt memory, which can crash the app or be used to modify memory during an attack.","severity":"high","cvss":8.8,"epss":0.02286,"exploited":true,"exploited_at":"2021-11-03T00:00:00+00:00","products":[{"name":"Apple iOS, iPadOS, and watchOS","fixed":[],"affected":"","ecosystem":"vendor"}],"ecosystems":["vendor"],"tags":["apple-mail","exploited","ios","ipados","vendor","watchos"],"not_affected_if":["fully-patched-devices"],"how_to_check":null,"fix":"Update iOS, iPadOS and watchOS to a release that includes Apple's fix; CISA says to apply updates per vendor instructions.","status":"open","published_at":"2020-06-09T17:15:13+00:00","first_seen_at":"2026-10-23T19:11:53+00:00","triaged_at":"2026-10-23T21:39:40+00:00","updated_at":"2026-10-23T21:57:35+00:00","category":"vendor","confidence":0.6,"triage":{"at":"2026-10-23T21:39:40Z","model":"claude-haiku-5-5","output":{"fix":"Update iOS, iPadOS and watchOS to a release that includes Apple's fix; CISA says to apply updates per vendor instructions.","reach":"internet","impact":"high","summary":"Apple's iOS, iPadOS and watchOS Mail app has an out-of-bounds write flaw triggered when it processes a specially crafted email. An attacker can corrupt memory, which can crash the app or be used to modify memory during an attack.","category":"vendor","who_cares":["ios","ipados","watchos","apple-mail"],"confidence":0.6,"needs_auth":"no","worst_case":"Memory corruption in Mail could allow code execution on the device","analyst_note":"Confirm the fixed iOS/iPadOS/watchOS versions and the exact memory-modification impact at Apple's security advisory for CVE-2020-9818.","how_to_check":"unknown","needs_analyst":true,"not_affected_if":["fully-patched-devices"],"user_interaction":"no","needs_special_setup":"no","severity_if_unknown":"high"},"cost_usd":0.00047,"input_tokens":2875,"output_tokens":365,"severity_before":"unknown"},"analyst_status":"queued","analyst_note":"Confirm the fixed iOS/iPadOS/watchOS versions and the exact memory-modification impact at Apple's security advisory for CVE-2020-9818.","search":"'-2020':18A,21A '-9818':19A,22A '12.4.7':103C '13.5':98C,101C '6.2.5':105C 'address':87C 'and':26A 'app':43B,69B 'appl':1A,6A,29B,36B 'apple':23A 'apple-mail':28B 'applic':119C 'attack':61B,78B 'bound':14A,49B,83C,90C 'check':91C 'corrupt':63B 'craft':58B,109C 'crash':67B 'cve':17A,20A 'email':59B 'exploit':31B 'fix':95C 'flaw':51B 'improv':89C 'io':2A,7A,32B,38B,97C,102C 'ios':24A 'ipado':3A,8A,33B,39B,100C 'ipados':25A 'issu':85C,93C 'lead':113C 'mail':30B,42B,110C 'malici':108C 'may':112C 'memori':64B,75B,116C 'messag':111C 'modif':117C 'modifi':74B 'out-of-bound':11A,46B,80C 'process':55B,106C 'special':57B 'termin':120C 'trigger':52B 'unexpect':115C 'use':72B 'vendor':34B 'vulner':16A 'watcho':5A,10A,35B,41B,104C 'watchos':27A 'write':15A,50B,84C","nicknames":[],"mitigations":[],"who_affected":null,"tier":null,"verified":{},"analyst_revisit_at":null,"first_public_at":"2020-06-09T17:15:13+00:00","kev":{"dateAdded":"2021-11-03","dueDate":"2022-05-03","requiredAction":"Apply updates per vendor instructions.","knownRansomwareCampaignUse":"Unknown"},"cvss_vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","cvss_by":"nvd@nist.gov","poc_count":0,"sources":[{"source":"kev","external_id":"CVE-2020-9818","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2020-9818","severity":null,"published_at":"2021-11-03T00:00:00+00:00","modified_at":null,"first_seen_at":"2026-10-23T19:11:53+00:00","fetched_at":"2026-10-25T11:39:17+00:00","note":null},{"source":"epss","external_id":"CVE-2020-9818","url":"https://api.first.org/data/v1/epss?cve=CVE-2020-9818","severity":null,"published_at":null,"modified_at":null,"first_seen_at":"2026-10-23T19:13:44+00:00","fetched_at":"2026-10-23T19:13:44+00:00","note":null},{"source":"nvd","external_id":"CVE-2020-9818","url":"https://nvd.nist.gov/vuln/detail/CVE-2020-9818","severity":null,"published_at":"2020-06-09T17:15:13+00:00","modified_at":"2026-06-17T03:28:37+00:00","first_seen_at":"2026-10-23T21:57:35+00:00","fetched_at":"2026-10-23T21:57:35+00:00","note":null}],"documents":[],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}