[oe-commits] Wenzong Fan : krb5: fix CVE-2014-5351
git at git.openembedded.org
git at git.openembedded.org
Wed Dec 3 14:15:43 UTC 2014
Module: meta-openembedded.git
Branch: dizzy
Commit: 510b7a9d8d5dda07120df5866507742a626478c1
URL: http://git.openembedded.org/?p=meta-openembedded.git&a=commit;h=510b7a9d8d5dda07120df5866507742a626478c1
Author: Wenzong Fan <wenzong.fan at windriver.com>
Date: Wed Nov 12 03:25:19 2014 -0500
krb5: fix CVE-2014-5351
The kadm5_randkey_principal_3 function in lib/kadm5/srv/svr_principal.c
in kadmind in MIT Kerberos 5 (aka krb5) before 1.13 sends old keys in a
response to a -randkey -keepold request, which allows remote authentic-
ated users to forge tickets by leveraging administrative access.
This back-ported patch fixes CVE-2014-5351.
Signed-off-by: Wenzong Fan <wenzong.fan at windriver.com>
Signed-off-by: Martin Jansa <Martin.Jansa at gmail.com>
Signed-off-by: Armin Kuster <akuster808 at gmail.com>
---
...rn-only-new-keys-in-randkey-CVE-2014-5351.patch | 92 ++++++++++++++++++++++
meta-oe/recipes-connectivity/krb5/krb5_1.12.2.bb | 1 +
2 files changed, 93 insertions(+)
diff --git a/meta-oe/recipes-connectivity/krb5/krb5/0001-Return-only-new-keys-in-randkey-CVE-2014-5351.patch b/meta-oe/recipes-connectivity/krb5/krb5/0001-Return-only-new-keys-in-randkey-CVE-2014-5351.patch
new file mode 100644
index 0000000..0852661
--- /dev/null
+++ b/meta-oe/recipes-connectivity/krb5/krb5/0001-Return-only-new-keys-in-randkey-CVE-2014-5351.patch
@@ -0,0 +1,92 @@
+From af0ed4df4dfae762ab5fb605f5a0c8f59cb4f6ca Mon Sep 17 00:00:00 2001
+From: Greg Hudson <ghudson at mit.edu>
+Date: Thu, 21 Aug 2014 13:52:07 -0400
+Subject: [PATCH] Return only new keys in randkey [CVE-2014-5351]
+
+In kadmind's randkey operation, if a client specifies the keepold
+flag, do not include the preserved old keys in the response.
+
+CVE-2014-5351:
+
+An authenticated remote attacker can retrieve the current keys for a
+service principal when generating a new set of keys for that
+principal. The attacker needs to be authenticated as a user who has
+the elevated privilege for randomizing the keys of other principals.
+
+Normally, when a Kerberos administrator randomizes the keys of a
+service principal, kadmind returns only the new keys. This prevents
+an administrator who lacks legitimate privileged access to a service
+from forging tickets to authenticate to that service. If the
+"keepold" flag to the kadmin randkey RPC operation is true, kadmind
+retains the old keys in the KDC database as intended, but also
+unexpectedly returns the old keys to the client, which exposes the
+service to ticket forgery attacks from the administrator.
+
+A mitigating factor is that legitimate clients of the affected service
+will start failing to authenticate to the service once they begin to
+receive service tickets encrypted in the new keys. The affected
+service will be unable to decrypt the newly issued tickets, possibly
+alerting the legitimate administrator of the affected service.
+
+CVSSv2: AV:N/AC:H/Au:S/C:P/I:N/A:N/E:POC/RL:OF/RC:C
+
+[tlyu at mit.edu: CVE description and CVSS score]
+
+ticket: 8018 (new)
+target_version: 1.13
+tags: pullup
+
+Upstream-Status: Backport
+---
+ src/lib/kadm5/srv/svr_principal.c | 21 ++++++++++++++++++---
+ 1 files changed, 18 insertions(+), 3 deletions(-)
+
+diff --git a/lib/kadm5/srv/svr_principal.c b/lib/kadm5/srv/svr_principal.c
+index 5d358bd..d4e74cc 100644
+--- a/lib/kadm5/srv/svr_principal.c
++++ b/lib/kadm5/srv/svr_principal.c
+@@ -344,6 +344,20 @@ check_1_6_dummy(kadm5_principal_ent_t entry, long mask,
+ *passptr = NULL;
+ }
+
++/* Return the number of keys with the newest kvno. Assumes that all key data
++ * with the newest kvno are at the front of the key data array. */
++static int
++count_new_keys(int n_key_data, krb5_key_data *key_data)
++{
++ int n;
++
++ for (n = 1; n < n_key_data; n++) {
++ if (key_data[n - 1].key_data_kvno != key_data[n].key_data_kvno)
++ return n;
++ }
++ return n_key_data;
++}
++
+ kadm5_ret_t
+ kadm5_create_principal(void *server_handle,
+ kadm5_principal_ent_t entry, long mask,
+@@ -1593,7 +1607,7 @@ kadm5_randkey_principal_3(void *server_handle,
+ osa_princ_ent_rec adb;
+ krb5_int32 now;
+ kadm5_policy_ent_rec pol;
+- int ret, last_pwd;
++ int ret, last_pwd, n_new_keys;
+ krb5_boolean have_pol = FALSE;
+ kadm5_server_handle_t handle = server_handle;
+ krb5_keyblock *act_mkey;
+@@ -1686,8 +1700,9 @@ kadm5_randkey_principal_3(void *server_handle,
+ kdb->fail_auth_count = 0;
+
+ if (keyblocks) {
+- ret = decrypt_key_data(handle->context,
+- kdb->n_key_data, kdb->key_data,
++ /* Return only the new keys added by krb5_dbe_crk. */
++ n_new_keys = count_new_keys(kdb->n_key_data, kdb->key_data);
++ ret = decrypt_key_data(handle->context, n_new_keys, kdb->key_data,
+ keyblocks, n_keys);
+ if (ret)
+ goto done;
+--
+1.7.4.1
+
diff --git a/meta-oe/recipes-connectivity/krb5/krb5_1.12.2.bb b/meta-oe/recipes-connectivity/krb5/krb5_1.12.2.bb
index d3c643c..72de38b 100644
--- a/meta-oe/recipes-connectivity/krb5/krb5_1.12.2.bb
+++ b/meta-oe/recipes-connectivity/krb5/krb5_1.12.2.bb
@@ -22,6 +22,7 @@ inherit autotools-brokensep binconfig perlnative
SHRT_VER = "${@oe.utils.trim_version("${PV}", 2)}"
SRC_URI = "http://web.mit.edu/kerberos/dist/${BPN}/${SHRT_VER}/${BP}-signed.tar \
file://0001-aclocal-Add-parameter-to-disable-keyutils-detection.patch \
+ file://0001-Return-only-new-keys-in-randkey-CVE-2014-5351.patch \
file://debian-suppress-usr-lib-in-krb5-config.patch;striplevel=2 \
file://crosscompile_nm.patch \
file://etc/init.d/krb5-kdc \
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