Detections
Analytics
CVE-2017-17439
high
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.
References
https://www.debian.org/security/2017/dsa-4055
https://github.com/heimdal/heimdal/issues/353
https://github.com/heimdal/heimdal/commit/1a6a6e462dc2ac6111f9e02c6852ddec4849b887
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=878144
http://www.h5l.org/pipermail/heimdal-discuss/2017-August/000259.html
http://www.h5l.org/pipermail/heimdal-announce/2017-December/000008.html