{"id":"UBUNTU-CVE-2017-17439","details":"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function in lib/asn1/der_length.c.","modified":"2025-07-16T06:30:46.209935Z","published":"2017-12-06T15:29:00Z","withdrawn":"2025-07-18T16:44:16Z","upstream":["CVE-2017-17439"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2017-17439"},{"type":"REPORT","url":"http://www.h5l.org/pipermail/heimdal-discuss/2017-August/000259.html"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2017-17439"}],"affected":[{"package":{"name":"heimdal","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/heimdal@7.5.0+dfsg-1?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"7.5.0+dfsg-1"}]}],"versions":["7.4.0.dfsg.1-2"],"ecosystem_specific":{"binaries":[{"binary_name":"heimdal-clients","binary_version":"7.5.0+dfsg-1"},{"binary_name":"heimdal-clients-dbgsym","binary_version":"7.5.0+dfsg-1"},{"binary_name":"heimdal-dev","binary_version":"7.5.0+dfsg-1"},{"binary_name":"heimdal-docs","binary_version":"7.5.0+dfsg-1"},{"binary_name":"heimdal-kcm","binary_version":"7.5.0+dfsg-1"},{"binary_name":"heimdal-kcm-dbgsym","binary_version":"7.5.0+dfsg-1"},{"binary_name":"heimdal-kdc","binary_version":"7.5.0+dfsg-1"},{"binary_name":"heimdal-kdc-dbgsym","binary_version":"7.5.0+dfsg-1"},{"binary_name":"heimdal-multidev","binary_version":"7.5.0+dfsg-1"},{"binary_name":"heimdal-multidev-dbgsym","binary_version":"7.5.0+dfsg-1"},{"binary_name":"heimdal-servers","binary_version":"7.5.0+dfsg-1"},{"binary_name":"heimdal-servers-dbgsym","binary_version":"7.5.0+dfsg-1"},{"binary_name":"libasn1-8-heimdal","binary_version":"7.5.0+dfsg-1"},{"binary_name":"libasn1-8-heimdal-dbgsym","binary_version":"7.5.0+dfsg-1"},{"binary_name":"libgssapi3-heimdal","binary_version":"7.5.0+dfsg-1"},{"binary_name":"libgssapi3-heimdal-dbgsym","binary_version":"7.5.0+dfsg-1"},{"binary_name":"libhcrypto4-heimdal","binary_version":"7.5.0+dfsg-1"},{"binary_name":"libhcrypto4-heimdal-dbgsym","binary_version":"7.5.0+dfsg-1"},{"binary_name":"libhdb9-heimdal","binary_version":"7.5.0+dfsg-1"},{"binary_name":"libhdb9-heimdal-dbgsym","binary_version":"7.5.0+dfsg-1"},{"binary_name":"libheimbase1-heimdal","binary_version":"7.5.0+dfsg-1"},{"binary_name":"libheimbase1-heimdal-dbgsym","binary_version":"7.5.0+dfsg-1"},{"binary_name":"libheimntlm0-heimdal","binary_version":"7.5.0+dfsg-1"},{"binary_name":"libheimntlm0-heimdal-dbgsym","binary_version":"7.5.0+dfsg-1"},{"binary_name":"libhx509-5-heimdal","binary_version":"7.5.0+dfsg-1"},{"binary_name":"libhx509-5-heimdal-dbgsym","binary_version":"7.5.0+dfsg-1"},{"binary_name":"libkadm5clnt7-heimdal","binary_version":"7.5.0+dfsg-1"},{"binary_name":"libkadm5clnt7-heimdal-dbgsym","binary_version":"7.5.0+dfsg-1"},{"binary_name":"libkadm5srv8-heimdal","binary_version":"7.5.0+dfsg-1"},{"binary_name":"libkadm5srv8-heimdal-dbgsym","binary_version":"7.5.0+dfsg-1"},{"binary_name":"libkafs0-heimdal","binary_version":"7.5.0+dfsg-1"},{"binary_name":"libkafs0-heimdal-dbgsym","binary_version":"7.5.0+dfsg-1"},{"binary_name":"libkdc2-heimdal","binary_version":"7.5.0+dfsg-1"},{"binary_name":"libkdc2-heimdal-dbgsym","binary_version":"7.5.0+dfsg-1"},{"binary_name":"libkrb5-26-heimdal","binary_version":"7.5.0+dfsg-1"},{"binary_name":"libkrb5-26-heimdal-dbgsym","binary_version":"7.5.0+dfsg-1"},{"binary_name":"libotp0-heimdal","binary_version":"7.5.0+dfsg-1"},{"binary_name":"libotp0-heimdal-dbgsym","binary_version":"7.5.0+dfsg-1"},{"binary_name":"libroken18-heimdal","binary_version":"7.5.0+dfsg-1"},{"binary_name":"libroken18-heimdal-dbgsym","binary_version":"7.5.0+dfsg-1"},{"binary_name":"libsl0-heimdal","binary_version":"7.5.0+dfsg-1"},{"binary_name":"libsl0-heimdal-dbgsym","binary_version":"7.5.0+dfsg-1"},{"binary_name":"libwind0-heimdal","binary_version":"7.5.0+dfsg-1"},{"binary_name":"libwind0-heimdal-dbgsym","binary_version":"7.5.0+dfsg-1"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2017/UBUNTU-CVE-2017-17439.json"}}],"schema_version":"1.7.3","severity":[{"type":"CVSS_V3","score":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},{"type":"Ubuntu","score":"medium"}]}