{"cve":"CVE-2017-17439","nvd":{"published":"2017-12-06T15:29:00.250","modified":"2026-06-17T01:10:48.137","status":"Modified","description":"In Heimdal through 7.4, remote unauthenticated attackers are able to crash the KDC by sending a crafted UDP packet containing empty data fields for client name or realm. The parser would unconditionally dereference NULL pointers in that case, leading to a segmentation fault. This is related to the _kdc_as_rep function in kdc/kerberos5.c and the der_length_visible_string function in lib/asn1/der_length.c.","cvss_v4":null,"cvss_v3":{"version":"3.0","vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5},"cwes":["CWE-476"],"references":["http://h5l.org/advisories.html?show=2017-12-08","http://www.h5l.org/pipermail/heimdal-announce/2017-December/000008.html","http://www.h5l.org/pipermail/heimdal-discuss/2017-August/000259.html","https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=878144","https://github.com/heimdal/heimdal/commit/1a6a6e462dc2ac6111f9e02c6852ddec4849b887"],"products":["debian:debian_linux","heimdal_project:heimdal"],"source":"nvd","synced_at":"2026-10-19T20:47:56.471723566+00:00"},"epss":{"cve":"CVE-2017-17439","score":0.03427,"percentile":0.88924,"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."]}