{"id":"CVE-2020-7247","kind":"vulnerability","aliases":["CVE-2020-7247"],"related":[],"title":"OpenBSD OpenSMTPD: OpenSMTPD Remote Code Execution Vulnerability","description":"smtp_mailaddr in smtp_session.c in OpenSMTPD 6.6, as used in OpenBSD 6.6 and other products, allows remote attackers to execute arbitrary commands as root via a crafted SMTP session, as demonstrated by shell metacharacters in a MAIL FROM field. This affects the \"uncommented\" default configuration. The issue exists because of an incorrect return value upon failure of input validation.","summary":"OpenSMTPD, the mail server shipped with OpenBSD and used in other products, has a flaw in its SMTP address parsing (smtp_mailaddr). A remote attacker who sends a crafted SMTP session can execute arbitrary commands as root.","severity":"critical","cvss":10.0,"epss":0.98972,"exploited":true,"exploited_at":"2022-03-25T00:00:00+00:00","products":[{"name":"OpenBSD OpenSMTPD","fixed":[],"affected":"","ecosystem":"vendor"}],"ecosystems":["vendor"],"tags":["exploited","infrastructure","mail-server","openbsd","opensmtpd","self-hosted"],"not_affected_if":["no-opensmtpd-running","other-mta-in-use"],"how_to_check":null,"fix":"Apply the OpenSMTPD update from the vendor (OpenBSD or your distribution) per CISA's required action; exact fixed version: unknown","status":"open","published_at":"2020-01-29T16:15:12+00:00","first_seen_at":"2026-10-23T19:11:52+00:00","triaged_at":"2026-10-23T21:20:12+00:00","updated_at":"2026-10-23T21:57:35+00:00","category":"infrastructure","confidence":0.8,"triage":{"at":"2026-10-23T21:20:12Z","model":"claude-haiku-5-5","output":{"fix":"Apply the OpenSMTPD update from the vendor (OpenBSD or your distribution) per CISA's required action; exact fixed version: unknown","reach":"internet","impact":"high","summary":"OpenSMTPD, the mail server shipped with OpenBSD and used in other products, has a flaw in its SMTP address parsing (smtp_mailaddr). A remote attacker who sends a crafted SMTP session can execute arbitrary commands as root.","category":"infrastructure","who_cares":["openbsd","opensmtpd","self-hosted","mail-server"],"confidence":0.8,"needs_auth":"no","worst_case":"Remote attacker runs arbitrary commands as root via SMTP","analyst_note":"Find the fixed OpenSMTPD version and affected range in the OpenBSD errata or vendor advisory; the sources give none, and how_to_check is unknown.","how_to_check":"unknown","needs_analyst":true,"not_affected_if":["no-opensmtpd-running","other-mta-in-use"],"user_interaction":"no","needs_special_setup":"unknown","severity_if_unknown":"critical"},"cost_usd":0.000485,"input_tokens":2860,"output_tokens":397,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-2020':9A,12A '-7247':10A,13A '6.6':70C,75C 'address':44B 'affect':104C 'allow':79C 'arbitrari':59B,84C 'attack':50B,81C 'code':5A 'command':60B,85C 'configur':108C 'craft':54B,90C 'cve':8A,11A 'default':107C 'demonstr':94C 'execut':6A,58B,83C 'exist':111C 'exploit':16B 'failur':119C 'field':102C 'flaw':40B 'host':25B 'incorrect':115C 'infrastructur':17B 'input':121C 'issu':110C 'mail':19B,28B,100C 'mail-serv':18B 'mailaddr':47B,64C 'metacharact':97C 'openbsd':1A,14A,21B,32B,74C 'opensmtpd':2A,3A,15A,22B,26B,69C 'pars':45B 'product':37B,78C 'remot':4A,49B,80C 'return':116C 'root':62B,87C 'self':24B 'self-host':23B 'send':52B 'server':20B,29B 'session':56B,92C 'session.c':67C 'shell':96C 'ship':30B 'smtp':43B,46B,55B,63C,66C,91C 'uncom':106C 'upon':118C 'use':34B,72C 'valid':122C 'valu':117C 'via':88C 'vulner':7A","nicknames":[],"mitigations":[],"who_affected":null,"tier":null,"verified":{},"analyst_revisit_at":null,"first_public_at":"2020-01-29T16:15:12+00:00","kev":{"dateAdded":"2022-03-25","dueDate":"2022-04-15","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":"nvd@nist.gov","poc_count":0,"sources":[{"source":"kev","external_id":"CVE-2020-7247","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2020-7247","severity":null,"published_at":"2022-03-25T00:00:00+00:00","modified_at":null,"first_seen_at":"2026-10-23T19:11:52+00:00","fetched_at":"2026-10-25T20:35:36+00:00","note":null},{"source":"epss","external_id":"CVE-2020-7247","url":"https://api.first.org/data/v1/epss?cve=CVE-2020-7247","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-2020-7247","url":"https://nvd.nist.gov/vuln/detail/CVE-2020-7247","severity":null,"published_at":"2020-01-29T16:15:12+00:00","modified_at":"2026-06-17T03:24:35+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"}