* Mon May 4 2015 Roland Mainz <rmainz@redhat.com> - 1.13.1-4

- fix for CVE-2015-2694 (#1216133) "requires_preauth bypass
  in PKINIT-enabled KDC".
  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.
resolves: #1216134

krb5-1.13.2-CVE_2015_2694_requires_preauth_bypass_in_PKINIT_enabled_KDC.patch

@@ -0,0 +1,100 @@
+From e3b5a5e5267818c97750b266df50b6a3d4649604 Mon Sep 17 00:00:00 2001
+From: Greg Hudson <ghudson@mit.edu>
+Date: Tue, 24 Mar 2015 12:02:37 -0400
+Subject: [PATCH] Prevent requires_preauth bypass [CVE-2015-2694]
+
+In the OTP kdcpreauth module, don't set the TKT_FLG_PRE_AUTH bit until
+the request is successfully verified.  In the PKINIT kdcpreauth
+module, don't respond with code 0 on empty input or an unconfigured
+realm.  Together these bugs could cause the KDC preauth framework to
+erroneously treat a request as pre-authenticated.
+
+CVE-2015-2694:
+
+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.
+
+    CVSSv2 Vector: AV:N/AC:M/Au:N/C:P/I:P/A:N/E:POC/RL:OF/RC:C
+
+ticket: 8160 (new)
+target_version: 1.13.2
+tags: pullup
+subject: requires_preauth bypass in PKINIT-enabled KDC [CVE-2015-2694]
+---
+ src/plugins/preauth/otp/main.c          | 10 +++++++---
+ src/plugins/preauth/pkinit/pkinit_srv.c |  4 ++--
+ 2 files changed, 9 insertions(+), 5 deletions(-)
+
+diff --git a/src/plugins/preauth/otp/main.c b/src/plugins/preauth/otp/main.c
+index bf9c6a8..7941b4a 100644
+--- a/src/plugins/preauth/otp/main.c
++++ b/src/plugins/preauth/otp/main.c
+@@ -42,6 +42,7 @@ static krb5_preauthtype otp_pa_type_list[] =
+ struct request_state {
+     krb5_kdcpreauth_verify_respond_fn respond;
+     void *arg;
++    krb5_enc_tkt_part *enc_tkt_reply;
+ };
+ 
+ static krb5_error_code
+@@ -159,6 +160,9 @@ on_response(void *data, krb5_error_code retval, otp_response response)
+     if (retval == 0 && response != otp_response_success)
+         retval = KRB5_PREAUTH_FAILED;
+ 
++    if (retval == 0)
++        rs.enc_tkt_reply->flags |= TKT_FLG_PRE_AUTH;
++
+     rs.respond(rs.arg, retval, NULL, NULL, NULL);
+ }
+ 
+@@ -263,8 +267,6 @@ otp_verify(krb5_context context, krb5_data *req_pkt, krb5_kdc_req *request,
+     krb5_data d, plaintext;
+     char *config;
+ 
+-    enc_tkt_reply->flags |= TKT_FLG_PRE_AUTH;
+-
+     /* Get the FAST armor key. */
+     armor_key = cb->fast_armor(context, rock);
+     if (armor_key == NULL) {
+@@ -298,12 +300,14 @@ otp_verify(krb5_context context, krb5_data *req_pkt, krb5_kdc_req *request,
+         goto error;
+     }
+ 
+-    /* Create the request state. */
++    /* Create the request state.  Save the response callback, and the
++     * enc_tkt_reply pointer so we can set the TKT_FLG_PRE_AUTH flag later. */
+     rs = k5alloc(sizeof(struct request_state), &retval);
+     if (rs == NULL)
+         goto error;
+     rs->arg = arg;
+     rs->respond = respond;
++    rs->enc_tkt_reply = enc_tkt_reply;
+ 
+     /* Get the principal's OTP configuration string. */
+     retval = cb->get_string(context, rock, "otp", &config);
+diff --git a/src/plugins/preauth/pkinit/pkinit_srv.c b/src/plugins/preauth/pkinit/pkinit_srv.c
+index b472741..5b1d73e 100644
+--- a/src/plugins/preauth/pkinit/pkinit_srv.c
++++ b/src/plugins/preauth/pkinit/pkinit_srv.c
+@@ -301,7 +301,7 @@ pkinit_server_verify_padata(krb5_context context,
+ 
+     pkiDebug("pkinit_verify_padata: entered!\n");
+     if (data == NULL || data->length <= 0 || data->contents == NULL) {
+-        (*respond)(arg, 0, NULL, NULL, NULL);
++        (*respond)(arg, EINVAL, NULL, NULL, NULL);
+         return;
+     }
+ 
+@@ -313,7 +313,7 @@ pkinit_server_verify_padata(krb5_context context,
+ 
+     plgctx = pkinit_find_realm_context(context, moddata, request->server);
+     if (plgctx == NULL) {
+-        (*respond)(arg, 0, NULL, NULL, NULL);
++        (*respond)(arg, EINVAL, NULL, NULL, NULL);
+         return;
+     }
+ 

krb5.spec

@@ -43,7 +43,7 @@
 Summary: The Kerberos network authentication system
 Name: krb5
 Version: 1.13.1
-Release: 3%{?dist}
+Release: 4%{?dist}
 # - Maybe we should explode from the now-available-to-everybody tarball instead?
 # http://web.mit.edu/kerberos/dist/krb5/1.13/krb5-1.13.1-signed.tar
 # - The sources below are stored in a lookaside cache. Upload with
@@ -96,6 +96,7 @@ Patch134: krb5-1.11-kpasswdtest.patch
 Patch136: krb5-socket_wrapper_eventfd_prototype_mismatch.patch
 Patch140: krb5-1.14-Support-KDC_ERR_MORE_PREAUTH_DATA_REQUIRED.patch
 Patch141: krb5-1.12.1-CVE_2014_5355_fix_krb5_read_message_handling.patch
+Patch142: krb5-1.13.2-CVE_2015_2694_requires_preauth_bypass_in_PKINIT_enabled_KDC.patch
 
 License: MIT
 URL: http://web.mit.edu/kerberos/www/
@@ -319,6 +320,7 @@ ln NOTICE LICENSE
 
 %patch140 -p1 -b .krb5-1.14-support-kdc_err_more_preauth_data_required
 %patch141 -p1 -b .krb5-1.12.1-cve_2014_5355_fix_krb5_read_message_handling
+%patch142 -p1 -b .krb5-1.13.2-cve_2015_2694_requires_preauth_bypass_in_pkinit_enabled_kdc
 
 # Take the execute bit off of documentation.
 chmod -x doc/krb5-protocol/*.txt doc/ccapi/*.html
@@ -1002,6 +1004,16 @@ exit 0
 
 
 %changelog
+* Mon May 4 2015 Roland Mainz <rmainz@redhat.com> - 1.13.1-4
+- fix for CVE-2015-2694 (#1216133) "requires_preauth bypass
+  in PKINIT-enabled KDC".
+  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.
+
 * Wed Mar 25 2015 Roland Mainz <rmainz@redhat.com> - 1.13.1-3
 - Add temporay workaround for RH bug #1204646 ("krb5-config
   returns wrong -specs path") which modifies krb5-config post