{"id":"CVE-2023-41991","kind":"vulnerability","aliases":["CVE-2023-41991"],"related":[],"title":"A certificate validation issue was addressed","description":"A certificate validation issue was addressed. This issue is fixed in macOS Ventura 13.6, iOS 16.7 and iPadOS 16.7. A malicious app may be able to bypass signature validation. Apple is aware of a report that this issue may have been actively exploited against versions of iOS before iOS 16.7.","summary":"Apple iOS, iPadOS, macOS and watchOS have an improper certificate validation flaw that lets a malicious app bypass signature validation. CISA lists it as known exploited in the wild.","severity":"high","cvss":5.5,"epss":null,"exploited":true,"exploited_at":"2023-09-25T00:00:00+00:00","products":[{"name":"Apple Multiple Products","fixed":[],"affected":"","ecosystem":"vendor"},{"name":"apple ipados","fixed":["16.7"],"affected":"< 16.7","ecosystem":"vendor"},{"name":"apple ipados","fixed":[],"affected":"= 17.0","ecosystem":"vendor"},{"name":"apple iphone os","fixed":["16.7"],"affected":"< 16.7","ecosystem":"vendor"},{"name":"apple iphone os","fixed":[],"affected":"= 17.0","ecosystem":"vendor"},{"name":"apple macos","fixed":["13.6"],"affected":">= 13.0, < 13.6","ecosystem":"vendor"}],"ecosystems":["vendor"],"tags":["apple-devices","exploited","infrastructure","ios","ipados","macos","watchos"],"not_affected_if":["unknown"],"how_to_check":null,"fix":"Apply mitigations per vendor instructions or update to a fixed Apple OS release; the sources do not name the fixed versions.","status":"open","published_at":"2023-09-21T19:15:11+00:00","first_seen_at":"2026-10-23T19:11:51+00:00","triaged_at":"2026-10-23T21:04:33+00:00","updated_at":"2026-10-23T22:29:04+00:00","category":"infrastructure","confidence":0.6,"triage":{"at":"2026-10-23T21:04:33Z","model":"claude-haiku-5-5","output":{"fix":"Apply mitigations per vendor instructions or update to a fixed Apple OS release; the sources do not name the fixed versions.","reach":"local","impact":"high","summary":"Apple iOS, iPadOS, macOS and watchOS have an improper certificate validation flaw that lets a malicious app bypass signature validation. CISA lists it as known exploited in the wild.","category":"infrastructure","who_cares":["ios","ipados","macos","watchos","apple-devices"],"confidence":0.6,"needs_auth":"unknown","worst_case":"malicious app bypasses code signature checks and runs untrusted code","analyst_note":"Find Apple's security advisory for CVE-2023-41991 to get fixed OS versions and the vendor mitigation steps, starting from the CISA KEV entry.","how_to_check":"unknown","needs_analyst":true,"not_affected_if":["unknown"],"user_interaction":"unknown","needs_special_setup":"unknown","severity_if_unknown":"high"},"cost_usd":0.000457,"input_tokens":2819,"output_tokens":351,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-2023':8A,11A '-41991':9A,12A '13.6':79C '16.7':81C,84C,115C 'abl':90C 'activ':107C 'address':6A,71C 'app':53B,87C 'appl':29B,37B,95C 'apple':13A,16A,18A,20A,23A,26A 'apple-devic':28B 'awar':97C 'bypass':54B,92C 'certif':2A,46B,67C 'cisa':57B 'cve':7A,10A 'devic':30B 'exploit':31B,62B,108C 'fix':75C 'flaw':48B 'improp':45B 'infrastructur':32B 'io':33B,38B,80C,112C,114C 'ipado':34B,39B,83C 'ipados':17A,19A 'iphone':21A,24A 'issu':4A,69C,73C,103C 'known':61B 'let':50B 'list':58B 'maco':35B,40B,77C 'macos':27A 'malici':52B,86C 'may':88C,104C 'multiple':14A 'os':22A,25A 'products':15A 'report':100C 'signatur':55B,93C 'valid':3A,47B,56B,68C,94C 'ventura':78C 'version':110C 'watcho':36B,42B 'wild':65B","nicknames":[],"mitigations":[],"who_affected":null,"tier":null,"verified":{},"analyst_revisit_at":null,"first_public_at":"2023-09-21T19:15:11+00:00","kev":{"dateAdded":"2023-09-25","dueDate":"2023-10-16","requiredAction":"Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.","knownRansomwareCampaignUse":"Unknown"},"cvss_vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N","cvss_by":"nvd@nist.gov","poc_count":0,"sources":[{"source":"kev","external_id":"CVE-2023-41991","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2023-41991","severity":null,"published_at":"2023-09-25T00:00:00+00:00","modified_at":null,"first_seen_at":"2026-10-23T19:11:51+00:00","fetched_at":"2026-10-25T14:39:39+00:00","note":null},{"source":"nvd","external_id":"CVE-2023-41991","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-41991","severity":null,"published_at":"2023-09-21T19:15:11+00:00","modified_at":"2026-06-17T06:23:13+00:00","first_seen_at":"2026-10-23T22:29:04+00:00","fetched_at":"2026-10-23T22:29:04+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"}