[oe] [meta-oe][PATCH 1/2] krb5: fix CVE-2017-11368
Martin Jansa
martin.jansa at gmail.com
Wed Aug 30 09:40:57 UTC 2017
done
On Wed, Aug 30, 2017 at 11:30 AM, Kang Kai <Kai.Kang at windriver.com> wrote:
> On 2017年08月28日 21:59, kai.kang at windriver.com wrote:
>
>> From: Kai Kang <kai.kang at windriver.com>
>>
>> Issue: CVE-2017-11368
>>
>> Backport patch to fix CVE-2017-11368 for krb5.
>>
>> (LOCAL REV: NOT UPSTREAM) -- Send to oe-devel on 20170828
>>
>
> Hi Martin,
>
> Ooops. I forgot to remove inner informations in the commit message.
>
> Should I send V2 to remove the following 2 lines?
>
> Issue: CVE-2017-11368
>
> (LOCAL REV: NOT UPSTREAM) -- Send to oe-devel on 20170828
>
>
> Sorry for the inconvenience.
>
>
> --Kai
>
>
>
>> Signed-off-by: Kai Kang <kai.kang at windriver.com>
>> ---
>> .../krb5/krb5/fix-CVE-2017-11368.patch | 116
>> +++++++++++++++++++++
>> meta-oe/recipes-connectivity/krb5/krb5_1.15.1.bb | 1 +
>> 2 files changed, 117 insertions(+)
>> create mode 100644 meta-oe/recipes-connectivity/k
>> rb5/krb5/fix-CVE-2017-11368.patch
>>
>> diff --git a/meta-oe/recipes-connectivity/krb5/krb5/fix-CVE-2017-11368.patch
>> b/meta-oe/recipes-connectivity/krb5/krb5/fix-CVE-2017-11368.patch
>> new file mode 100644
>> index 000000000..a2eb7bc02
>> --- /dev/null
>> +++ b/meta-oe/recipes-connectivity/krb5/krb5/fix-CVE-2017-11368.patch
>> @@ -0,0 +1,116 @@
>> +Upstream-Status: Backport [https://github.com/krb5/krb5/
>> commit/ffb35baac6981f9e8914f8f3bffd37f284b85970]
>> +
>> +Backport patch to fix CVE-2017-11368.
>> +
>> +Signed-off-by: Kai Kang <kai.kang at windriver.com>
>> +---
>> +From ffb35baac6981f9e8914f8f3bffd37f284b85970 Mon Sep 17 00:00:00 2001
>> +From: Greg Hudson <ghudson at mit.edu>
>> +Date: Thu, 13 Jul 2017 12:14:20 -0400
>> +Subject: [PATCH] Prevent KDC unset status assertion failures
>> +
>> +Assign status values if S4U2Self padata fails to decode, if an
>> +S4U2Proxy request uses invalid KDC options, or if an S4U2Proxy request
>> +uses an evidence ticket which does not match the canonicalized request
>> +server principal name. Reported by Samuel Cabrero.
>> +
>> +If a status value is not assigned during KDC processing, default to
>> +"UNKNOWN_REASON" rather than failing an assertion. This change will
>> +prevent future denial of service bugs due to similar mistakes, and
>> +will allow us to omit assigning status values for unlikely errors such
>> +as small memory allocation failures.
>> +
>> +CVE-2017-11368:
>> +
>> +In MIT krb5 1.7 and later, an authenticated attacker can cause an
>> +assertion failure in krb5kdc by sending an invalid S4U2Self or
>> +S4U2Proxy request.
>> +
>> + CVSSv3 Vector: AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H/E:H/RL:O/RC:C
>> +
>> +ticket: 8599 (new)
>> +target_version: 1.15-next
>> +target_version: 1.14-next
>> +tags: pullup
>> +---
>> + src/kdc/do_as_req.c | 4 ++--
>> + src/kdc/do_tgs_req.c | 3 ++-
>> + src/kdc/kdc_util.c | 10 ++++++++--
>> + 3 files changed, 12 insertions(+), 5 deletions(-)
>> +
>> +diff --git a/src/kdc/do_as_req.c b/src/kdc/do_as_req.c
>> +index 2d3ad13..9b256c8 100644
>> +--- a/src/kdc/do_as_req.c
>> ++++ b/src/kdc/do_as_req.c
>> +@@ -366,8 +366,8 @@ finish_process_as_req(struct as_req_state *state,
>> krb5_error_code errcode)
>> + did_log = 1;
>> +
>> + egress:
>> +- if (errcode != 0)
>> +- assert (state->status != 0);
>> ++ if (errcode != 0 && state->status == NULL)
>> ++ state->status = "UNKNOWN_REASON";
>> +
>> + au_state->status = state->status;
>> + au_state->reply = &state->reply;
>> +diff --git a/src/kdc/do_tgs_req.c b/src/kdc/do_tgs_req.c
>> +index cdc79ad..d8d6719 100644
>> +--- a/src/kdc/do_tgs_req.c
>> ++++ b/src/kdc/do_tgs_req.c
>> +@@ -823,7 +823,8 @@ process_tgs_req(struct server_handle *handle,
>> krb5_data *pkt,
>> + free(reply.enc_part.ciphertext.data);
>> +
>> + cleanup:
>> +- assert(status != NULL);
>> ++ if (status == NULL)
>> ++ status = "UNKNOWN_REASON";
>> + if (reply_key)
>> + krb5_free_keyblock(kdc_context, reply_key);
>> + if (errcode)
>> +diff --git a/src/kdc/kdc_util.c b/src/kdc/kdc_util.c
>> +index 778a629..b710aef 100644
>> +--- a/src/kdc/kdc_util.c
>> ++++ b/src/kdc/kdc_util.c
>> +@@ -1220,8 +1220,10 @@ kdc_process_for_user(kdc_realm_t
>> *kdc_active_realm,
>> + req_data.data = (char *)pa_data->contents;
>> +
>> + code = decode_krb5_pa_for_user(&req_data, &for_user);
>> +- if (code)
>> ++ if (code) {
>> ++ *status = "DECODE_PA_FOR_USER";
>> + return code;
>> ++ }
>> +
>> + code = verify_for_user_checksum(kdc_context, tgs_session,
>> for_user);
>> + if (code) {
>> +@@ -1320,8 +1322,10 @@ kdc_process_s4u_x509_user(krb5_context context,
>> + req_data.data = (char *)pa_data->contents;
>> +
>> + code = decode_krb5_pa_s4u_x509_user(&req_data, s4u_x509_user);
>> +- if (code)
>> ++ if (code) {
>> ++ *status = "DECODE_PA_S4U_X509_USER";
>> + return code;
>> ++ }
>> +
>> + code = verify_s4u_x509_user_checksum(context,
>> + tgs_subkey ? tgs_subkey :
>> +@@ -1624,6 +1628,7 @@ kdc_process_s4u2proxy_req(kdc_realm_t
>> *kdc_active_realm,
>> + * that is validated previously in validate_tgs_request().
>> + */
>> + if (request->kdc_options & (NON_TGT_OPTION |
>> KDC_OPT_ENC_TKT_IN_SKEY)) {
>> ++ *status = "INVALID_S4U2PROXY_OPTIONS";
>> + return KRB5KDC_ERR_BADOPTION;
>> + }
>> +
>> +@@ -1631,6 +1636,7 @@ kdc_process_s4u2proxy_req(kdc_realm_t
>> *kdc_active_realm,
>> + if (!krb5_principal_compare(kdc_context,
>> + server->princ, /* after canon */
>> + server_princ)) {
>> ++ *status = "EVIDENCE_TICKET_MISMATCH";
>> + return KRB5KDC_ERR_SERVER_NOMATCH;
>> + }
>> +
>> +--
>> +2.10.1
>> +
>> diff --git a/meta-oe/recipes-connectivity/krb5/krb5_1.15.1.bb
>> b/meta-oe/recipes-connectivity/krb5/krb5_1.15.1.bb
>> index 1de884d03..b515eb5dc 100644
>> --- a/meta-oe/recipes-connectivity/krb5/krb5_1.15.1.bb
>> +++ b/meta-oe/recipes-connectivity/krb5/krb5_1.15.1.bb
>> @@ -30,6 +30,7 @@ SRC_URI = "http://web.mit.edu/kerberos/d
>> ist/${BPN}/${SHRT_VER}/${BP}.tar.gz \
>> file://etc/default/krb5-admin-server \
>> file://krb5-kdc.service \
>> file://krb5-admin-server.service \
>> + file://fix-CVE-2017-11368.patch;striplevel=2 \
>> "
>> SRC_URI[md5sum] = "8022f3a1cde8463e44fd35ef42731f85"
>> SRC_URI[sha256sum] = "437c8831ddd5fde2a993fef425ded
>> b48468109bb3d3261ef838295045a89eb45"
>>
>
>
> --
> Regards,
> Neil | Kai Kang
>
>
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