{"cve":"CVE-2015-1798","nvd":{"published":"2015-04-08T10:59:04.610","modified":"2026-06-17T00:23:01.337","status":"Modified","description":"The symmetric-key feature in the receive function in ntp_proto.c in ntpd in NTP 4.x before 4.2.8p2 requires a correct MAC only if the MAC field has a nonzero length, which makes it easier for man-in-the-middle attackers to spoof packets by omitting the MAC.","cvss_v4":null,"cvss_v3":null,"cwes":["CWE-17"],"references":["http://bugs.ntp.org/show_bug.cgi?id=2779","http://lists.apple.com/archives/security-announce/2015/Jun/msg00002.html","http://lists.fedoraproject.org/pipermail/package-announce/2015-April/155863.html","http://lists.fedoraproject.org/pipermail/package-announce/2015-April/155864.html","http://lists.opensuse.org/opensuse-updates/2015-04/msg00052.html"],"products":["ntp:ntp"],"source":"nvd","synced_at":"2026-10-19T20:35:35.528235705+00:00"},"epss":{"cve":"CVE-2015-1798","score":0.02243,"percentile":0.82855,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}