PT-2017-14780 · Heimdal+1 · Heimdal+1

Michael Eder + 1 · Published 2017-12-06 · Updated 2018-08-16 · CVE-2017-17439

Positive Technologies (AI Summary)

CVSS v3.1

7.5

High

Base vector

AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Name of the Vulnerable Software and Affected Versions Heimdal versions prior to 7.5

Description The issue allows remote unauthenticated attackers to crash the KDC by sending a crafted UDP packet with empty data fields for client name or realm. This leads to a segmentation fault due to the parser unconditionally dereferencing NULL pointers. The problem 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.

Recommendations For Heimdal versions prior to 7.5, update to version 7.5 or later to resolve the issue. As a temporary workaround, consider restricting access to the KDC to minimize the risk of exploitation.

Fix

NULL Pointer Dereference

Weakness Enumeration

CWE-476

Related Identifiers

CVE-2017-17439

DSA-4055-1

MGASA-2017-0485

OPENSUSE-SU-2018_2376-1

OPENSUSE-SU-2024:10946-1

Affected Products

Heimdal

Suse

References · 29

• https://github.com/heimdal/heimdal/issues/353 · Patch
• https://osv.dev/vulnerability/ALPINE-CVE-2017-17439 · Vendor Advisory
• https://ubuntu.com/security/CVE-2017-17439 · Vendor Advisory
• https://debian.org/security/2017/dsa-4055 · Vendor Advisory
• https://security-tracker.debian.org/tracker/DSA-4055-1 · Vendor Advisory
• http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-17439 · Security Note
• https://osv.dev/vulnerability/DSA-4055-1 · Vendor Advisory
• https://security-tracker.debian.org/tracker/source-package/heimdal · Vendor Advisory
• https://osv.dev/vulnerability/DEBIAN-CVE-2017-17439 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2017-17439 · Security Note
• https://cve.org/CVERecord?id=CVE-2017-17439 · Security Note
• https://osv.dev/vulnerability/UBUNTU-CVE-2017-17439 · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2017-17439 · Vendor Advisory
• https://advisories.mageia.org/MGASA-2017-0485.html · Security Note
• https://security-tracker.debian.org/tracker/CVE-2017-17439 · Vendor Advisory