NULL pointer dereference in Heimdal Project
CVE-2017-17439
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.034 (88.8th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 89th percentile — 88.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.034 · newest: 0.034 · change: +0.000
Affected products
- Heimdal Project
- Debian Linux — versions 9.0
Weakness classification (CWE)
Public proof-of-concept exploits
References
- bugs.debian.org/cgi-bin/bugreport.cgi (Mailing List, Third Party Advisory, Issue Tracking)
- github.com/heimdal/heimdal/commit/1a6a6e462dc2ac6111f9e02c6852ddec4849b887 (Third Party Advisory)
- www.h5l.org/pipermail/heimdal-announce/2017-December/000008.html
- www.h5l.org/pipermail/heimdal-discuss/2017-August/000259.html (Third Party Advisory)
- github.com/heimdal/heimdal/issues/353 (Patch, Third Party Advisory)
- h5l.org/advisories.html
- www.debian.org/security/2017/dsa-4055 (vendor-advisory, Third Party Advisory)
Frequently asked questions
- What is CVE-2017-17439?
- CVE-2017-17439 is a high-severity vulnerability in Heimdal Project, classified under NULL Pointer Dereference. CVSS score: 7.5/10. Published 2017-12-06.
- How severe is CVE-2017-17439?
- High severity. CVSS v3 base score is 7.5 out of 10.
- Is CVE-2017-17439 known to be exploited?
- 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.