High severity7.5NVD Advisory· Published Dec 6, 2017· Updated Jun 17, 2026

CVE-2017-17439

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.

AI Insight

LLM-synthesized narrative grounded in this CVE's description and references.

Affected products

Heimdal/Heimdal2 versions
cpe:2.3:a:heimdal_project:heimdal:*:*:*:*:*:*:*:*+ 1 more
- cpe:2.3:a:heimdal_project:heimdal:*:*:*:*:*:*:*:*range: <=7.4.0
- (no CPE)range: <=7.4
Debian/linux
cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*

Patches

Vulnerability mechanics

References

github.com/heimdal/heimdal/issues/353nvdPatchThird Party Advisory
www.h5l.org/pipermail/heimdal-discuss/2017-August/000259.htmlnvdThird Party Advisory
bugs.debian.org/cgi-bin/bugreport.cginvdIssue TrackingMailing ListThird Party Advisory
github.com/heimdal/heimdal/commit/1a6a6e462dc2ac6111f9e02c6852ddec4849b887nvdThird Party Advisory
www.debian.org/security/2017/dsa-4055nvdThird Party Advisory
h5l.org/advisories.htmlnvd
www.h5l.org/pipermail/heimdal-announce/2017-December/000008.htmlnvd

News mentions

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