### [CVE-2017-17439](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-17439)
![](https://img.shields.io/static/v1?label=Product&message=n%2Fa&color=blue)
![](https://img.shields.io/static/v1?label=Version&message=n%2Fa%20&color=brightgreen)
![](https://img.shields.io/static/v1?label=Vulnerability&message=n%2Fa&color=brightgreen)

### 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.

### POC

#### Reference
- https://github.com/heimdal/heimdal/issues/353

#### Github
- https://github.com/ARPSyndicate/cvemon
- https://github.com/andir/nixos-issue-db-example