{"id":"CVE-2020-12063","aliases":["EUVD-2020-4379","GHSA-5wj2-9pm2-74vm"],"status":"disputed","title":"** DISPUTED ** A certain Postfix 2.10.1-7 package could allow an attacker to send an email from...","description":"A certain Postfix 2.10.1-7 package could allow an attacker to send an email from an arbitrary-looking sender via a homoglyph attack, as demonstrated by the similarity of \\xce\\xbf to the 'o' character. This is potentially relevant when the /etc/postfix/sender_login feature is used, because a spoofed outbound message that uses a configured sender address is blocked with a \"Sender address rejected: not logged in\" error message, but a spoofed outbound message that uses a homoglyph of a configured sender address is not blocked. NOTE: some third parties argue that any missed blocking of spoofed outbound messages - except for exact matches to a sender address in the /etc/postfix/sender_login file - is outside the design goals of Postfix and thus cannot be considered a Postfix vulnerability","severity":{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N","level":"medium","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-12","score":0.00935,"percentile":0.61242,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-345"],"published":"2020-04-24T11:59:03Z","modified":"2026-06-17T02:51:21Z","products":[{"vendor":"postfix","product":"postfix"}],"references":[{"url":"https://www.openwall.com/lists/oss-security/2020/04/23/3","tags":["x_refsource_MISC","x_transferred","Mailing List","Third Party Advisory"]},{"url":"https://www.openwall.com/lists/oss-security/2020/04/23/12","tags":["x_refsource_MISC","x_transferred","Exploit","Mailing List","Third Party Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2020-12063"},{"url":"https://github.com/advisories/GHSA-5wj2-9pm2-74vm"}],"sources":{"cve":[{"id":"CVE-2020-12063","description":"A certain Postfix 2.10.1-7 package could allow an attacker to send an email from an arbitrary-looking sender via a homoglyph attack, as demonstrated by the similarity of \\xce\\xbf to the 'o' character. This is potentially relevant when the /etc/postfix/sender_login feature is used, because a spoofed outbound message that uses a configured sender address is blocked with a \"Sender address rejected: not logged in\" error message, but a spoofed outbound message that uses a homoglyph of a configured sender address is not blocked. NOTE: some third parties argue that any missed blocking of spoofed outbound messages - except for exact matches to a sender address in the /etc/postfix/sender_login file - is outside the design goals of Postfix and thus cannot be considered a Postfix vulnerability","status":"disputed","published":"2020-04-24T11:59:03Z","modified":"2024-08-04T11:48:57.775Z","updated_at":"2026-11-02T14:35:52.925152Z"}],"euvd":[{"id":"EUVD-2020-4379","description":"A certain Postfix 2.10.1-7 package could allow an attacker to send an email from an arbitrary-looking sender via a homoglyph attack, as demonstrated by the similarity of \\xce\\xbf to the 'o' character. This is potentially relevant when the /etc/postfix/sender_login feature is used, because a spoofed outbound message that uses a configured sender address is blocked with a \"Sender address rejected: not logged in\" error message, but a spoofed outbound message that uses a homoglyph of a configured sender address is not blocked. NOTE: some third parties argue that any missed blocking of spoofed outbound messages - except for exact matches to a sender address in the /etc/postfix/sender_login file - is outside the design goals of Postfix and thus cannot be considered a Postfix vulnerability","status":"published","published":"2020-04-24T11:59:03Z","modified":"2024-08-04T11:48:57Z","updated_at":"2026-11-03T03:07:41.399649Z"}],"ghsa":[{"id":"GHSA-5wj2-9pm2-74vm","title":"** DISPUTED ** A certain Postfix 2.10.1-7 package could allow an attacker to send an email from...","description":"** DISPUTED ** A certain Postfix 2.10.1-7 package could allow an attacker to send an email from an arbitrary-looking sender via a homoglyph attack, as demonstrated by the similarity of \\xce\\xbf to the 'o' character. This is potentially relevant when the /etc/postfix/sender_login feature is used, because a spoofed outbound message that uses a configured sender address is blocked with a \"Sender address rejected: not logged in\" error message, but a spoofed outbound message that uses a homoglyph of a configured sender address is not blocked. NOTE: some third parties argue that any missed blocking of spoofed outbound messages - except for exact matches to a sender address in the /etc/postfix/sender_login file - is outside the design goals of Postfix and thus cannot be considered a Postfix vulnerability.","status":"published","published":"2022-05-24T17:16:25Z","modified":"2023-01-29T05:02:27Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N","level":"medium"}],"cwes":["CWE-345"],"updated_at":"2026-11-02T14:45:05.277553Z"}],"nvd":[{"id":"CVE-2020-12063","description":"A certain Postfix 2.10.1-7 package could allow an attacker to send an email from an arbitrary-looking sender via a homoglyph attack, as demonstrated by the similarity of \\xce\\xbf to the 'o' character. This is potentially relevant when the /etc/postfix/sender_login feature is used, because a spoofed outbound message that uses a configured sender address is blocked with a \"Sender address rejected: not logged in\" error message, but a spoofed outbound message that uses a homoglyph of a configured sender address is not blocked. NOTE: some third parties argue that any missed blocking of spoofed outbound messages - except for exact matches to a sender address in the /etc/postfix/sender_login file - is outside the design goals of Postfix and thus cannot be considered a Postfix vulnerability","status":"disputed","published":"2020-04-24T12:15:12.877Z","modified":"2026-06-17T02:51:21.883Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N","level":"medium","assessor":"primary"},{"version":"2.0","score":5,"vector":"AV:N/AC:L/Au:N/C:N/I:P/A:N","level":"medium","assessor":"primary"}],"updated_at":"2026-11-02T14:05:59.718774Z"}]}}