{"id":"CVE-2023-23397","kind":"vulnerability","aliases":["CVE-2023-23397"],"related":[],"title":"Microsoft Outlook Elevation of Privilege Vulnerability","description":"Microsoft Office Outlook contains a privilege escalation vulnerability that allows for a NTLM Relay attack against another service to authenticate as the user.\n\nCISA required action: Apply updates per vendor instructions.","summary":"Microsoft Office Outlook has a privilege escalation flaw that lets an attacker relay NTLM authentication to another service as the user. CISA lists it as actively exploited in the wild.","severity":"critical","cvss":9.8,"epss":null,"exploited":true,"exploited_at":"2023-03-14T00:00:00+00:00","products":[{"name":"Microsoft Office","fixed":[],"affected":"","ecosystem":"vendor"},{"name":"microsoft 365 apps","fixed":[],"affected":"","ecosystem":"vendor"},{"name":"microsoft office","fixed":[],"affected":"= 2019","ecosystem":"vendor"},{"name":"microsoft office long term servicing channel","fixed":[],"affected":"= 2021","ecosystem":"vendor"},{"name":"microsoft outlook","fixed":[],"affected":"= 2013","ecosystem":"vendor"},{"name":"microsoft outlook","fixed":[],"affected":"= 2016","ecosystem":"vendor"}],"ecosystems":["vendor"],"tags":["exploited","microsoft-office","outlook","package","windows"],"not_affected_if":["unknown"],"how_to_check":null,"fix":"Apply the Microsoft Office updates per vendor instructions, as CISA requires.","status":"open","published_at":"2023-03-14T00:00:00+00:00","first_seen_at":"2026-10-23T19:11:52+00:00","triaged_at":"2026-10-23T21:08:32+00:00","updated_at":"2026-10-23T22:29:04+00:00","category":"package","confidence":0.6,"triage":{"at":"2026-10-23T21:08:32Z","model":"claude-haiku-5-5","output":{"fix":"Apply the Microsoft Office updates per vendor instructions, as CISA requires.","reach":"network","impact":"high","summary":"Microsoft Office Outlook has a privilege escalation flaw that lets an attacker relay NTLM authentication to another service as the user. CISA lists it as actively exploited in the wild.","category":"package","who_cares":["microsoft-office","outlook","windows"],"confidence":0.6,"needs_auth":"no","worst_case":"Attacker relays user's NTLM authentication to other services, acting as the user","analyst_note":"Find the Microsoft advisory for CVE-2023-23397 to confirm affected and fixed Office builds and the detection method.","how_to_check":"unknown","needs_analyst":true,"not_affected_if":["unknown"],"user_interaction":"unknown","needs_special_setup":"unknown","severity_if_unknown":"high"},"cost_usd":0.000436,"input_tokens":2790,"output_tokens":313,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-2023':8A,11A '-23397':9A,12A '365':16A 'action':92C 'activ':62B 'allow':76C 'anoth':53B,83C 'appli':93C 'apps':17A 'attack':48B,81C 'authent':51B,86C 'channel':25A 'cisa':58B,90C 'contain':70C 'cve':7A,10A 'elev':3A 'escal':43B,73C 'exploit':30B,63B 'flaw':44B 'instruct':97C 'let':46B 'list':59B 'long':22A 'microsoft':1A,13A,15A,18A,20A,26A,28A,32B,37B,67C 'microsoft-offic':31B 'ntlm':50B,79C 'offic':33B,38B,68C 'office':14A,19A,21A 'outlook':2A,27A,29A,34B,39B,69C 'packag':35B 'per':95C 'privileg':5A,42B,72C 'relay':49B,80C 'requir':91C 'servic':54B,84C 'servicing':24A 'term':23A 'updat':94C 'user':57B,89C 'vendor':96C 'vulner':6A,74C 'wild':66B 'window':36B","nicknames":[],"mitigations":[],"who_affected":null,"tier":null,"verified":{},"analyst_revisit_at":null,"first_public_at":"2023-03-14T00:00:00+00:00","kev":{"dateAdded":"2023-03-14","dueDate":"2023-04-04","requiredAction":"Apply updates per vendor instructions.","knownRansomwareCampaignUse":"Unknown"},"cvss_vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cvss_by":"secure@microsoft.com","poc_count":0,"sources":[{"source":"kev","external_id":"CVE-2023-23397","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2023-23397","severity":null,"published_at":"2023-03-14T00:00:00+00:00","modified_at":null,"first_seen_at":"2026-10-23T19:11:52+00:00","fetched_at":"2026-10-25T15:39:41+00:00","note":null},{"source":"nvd","external_id":"CVE-2023-23397","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-23397","severity":null,"published_at":"2023-03-14T17:15:13+00:00","modified_at":"2026-06-17T05:37:01+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"}