Bug 1216133 (CVE-2015-2694)
|Summary:||CVE-2015-2694 krb5: issues in OTP and PKINIT kdcpreauth modules leading to requires_preauth bypass|
|Product:||[Other] Security Response||Reporter:||Martin Prpič <mprpic>|
|Component:||vulnerability||Assignee:||Red Hat Product Security <security-response-team>|
|Status:||CLOSED ERRATA||QA Contact:|
|Version:||unspecified||CC:||carnil, dpal, jplans, kerberos-dev-list, nalin, nathaniel, pkis, slawomir|
|Fixed In Version:||Doc Type:||Bug Fix|
A flaw was found in the OTP kdcpreauth module of MIT Kerberos. A remote attacker could use this flaw to bypass the requires_preauth flag on a client principal and obtain a ciphertext encrypted in the principal's long-term key. This ciphertext could be used to conduct an off-line dictionary attack against the user's password.
|Last Closed:||2015-11-20 05:43:50 UTC||Type:||---|
|oVirt Team:||---||RHEL 7.3 requirements from Atomic Host:|
|Cloudforms Team:||---||Target Upstream Version:|
|Bug Depends On:||1216134, 1218020|
|Bug Blocks:||1210268, 1216136|
Description Martin Prpič 2015-04-28 14:46:49 UTC
The following flaw was found in MIT Kerberos: In the OTP kdcpreauth module, the TKT_FLG_PRE_AUTH bit was set before the request was successfully verified. In the PKINIT kdcpreauth module, code 0 was returned on empty input or an unconfigured realm. Together, these bugs could cause the KDC preauth framework to erroneously treat a request as pre-authenticated. In MIT krb5 1.12 and later, when the KDC is configured with PKINIT support, an unauthenticated remote attacker can bypass the requires_preauth flag on a client principal and obtain a ciphertext encrypted in the principal's long-term key. This ciphertext could be used to conduct an off-line dictionary attack against the user's password. Upstream patch: https://github.com/krb5/krb5/commit/e3b5a5e5267818c97750b266df50b6a3d4649604
Comment 1 Martin Prpič 2015-04-28 14:47:38 UTC
Created krb5 tracking bugs for this issue: Affects: fedora-21 [bug 1216134]
Comment 3 Huzaifa S. Sidhpurwala 2015-05-04 03:38:29 UTC
Statement: This issue does not affect the version of krb5 package as shipped with Red Hat Enterprise Linux 5 and 6.
Comment 5 Fedora Update System 2015-05-11 19:02:49 UTC
krb5-1.13.1-3.fc22 has been pushed to the Fedora 22 stable repository. If problems still persist, please make note of it in this bug report.
Comment 6 Fedora Update System 2015-06-21 00:28:40 UTC
krb5-1.12.2-17.fc21 has been pushed to the Fedora 21 stable repository. If problems still persist, please make note of it in this bug report.