CVE-2017-15088

Name	CVE-2017-15088
Description	plugins/preauth/pkinit/pkinit_crypto_openssl.c in MIT Kerberos 5 (aka krb5) through 1.15.2 mishandles Distinguished Name (DN) fields, which allows remote attackers to execute arbitrary code or cause a denial of service (buffer overflow and application crash) in situations involving untrusted X.509 data, related to the get_matching_data and X509_NAME_oneline_ex functions. NOTE: this has security relevance only in use cases outside of the MIT Kerberos distribution, e.g., the use of get_matching_data in KDC certauth plugin code that is specific to Red Hat.
Source	CVE (at NVD; CERT, LWN, oss-sec, fulldisc, bugtraq, EDB, Metasploit, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, Mageia, GitHub code/issues, web search, more)
NVD severity	high (attack range: remote)
Debian Bugs	871698

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
krb5 (PTS)	jessie	1.12.1+dfsg-19+deb8u4	vulnerable
	jessie (security)	1.12.1+dfsg-19+deb8u5	vulnerable
	stretch	1.15-1+deb9u1	vulnerable
	buster	1.17-3	fixed
	bullseye, sid	1.17-6	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
krb5	source	(unstable)	1.15.2-2	unimportant		871698

Notes

https://github.com/krb5/krb5/pull/707
Fixed by: https://github.com/krb5/krb5/commit/fbb687db1088ddd894d975996e5f6a4252b9a2b4
Red Hat eanbled the code in question in the KDC and thus having it
exposed as network-facing issue. For Debian and upstream the code only
runs on client systems, and only with a certificate that is explicitly
configured locally, leading to a local kinit crash if passed a crafted
local certificate. This is hardly has any harmful security implication.