Vulnerability 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 Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Debian | Debian Linux | 9.0 |
| Heimdal Project | Heimdal | <= 7.4.0 |
Related Weaknesses (CWE)
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.htmlThird Party Advisory
- https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=878144Issue TrackingMailing ListThird Party Advisory
- https://github.com/heimdal/heimdal/commit/1a6a6e462dc2ac6111f9e02c6852ddec4849b8Third Party Advisory
- https://github.com/heimdal/heimdal/issues/353PatchThird Party Advisory
- https://www.debian.org/security/2017/dsa-4055Third Party Advisory
- 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.htmlThird Party Advisory
- https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=878144Issue TrackingMailing ListThird Party Advisory
- https://github.com/heimdal/heimdal/commit/1a6a6e462dc2ac6111f9e02c6852ddec4849b8Third Party Advisory
- https://github.com/heimdal/heimdal/issues/353PatchThird Party Advisory
- https://www.debian.org/security/2017/dsa-4055Third Party Advisory
FAQ
What is CVE-2017-17439?
CVE-2017-17439 is a vulnerability with a CVSS score of 7.5 (HIGH). 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 unconditional...
How severe is CVE-2017-17439?
CVE-2017-17439 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2017-17439?
Check the references section above for vendor advisories and patch information. Affected products include: Debian Debian Linux, Heimdal Project Heimdal.