Subject: [alpine-aports] [PATCH v3.4] main/samba: security fixes #6559

From: Sergey Lukin <[email-masked]>
Date: Fri, 30 Dec 2016 13:43:14 +0000

CVE-2016-2123: NDR Parsing ndr_pull_dnsp_name Heap-based Buffer Overflow Remote Code Execution Vulnerability
  https://www.samba.org/samba/security/CVE-2016-2123.html
CVE-2016-2125: Unconditional privilege delegation to Kerberos servers in trusted realms
  https://www.samba.org/samba/security/CVE-2016-2125.html
CVE-2016-2126: Flaws in Kerberos PAC validation can trigger privilege elevation
  https://www.samba.org/samba/security/CVE-2016-2126.html

https://www.samba.org/samba/history/security.html
---
 main/samba/APKBUILD                                |  13 +-
 ...CVE-2016-2123,CVE-2016-2125,CVE-2016-2126.patch | 200 +++++++++++++++++++++
 2 files changed, 212 insertions(+), 1 deletion(-)
 create mode 100644 main/samba/samba-4.4.7-security-20016-12-19-CVE-2016-2123,CVE-2016-2125,CVE-2016-2126.patch

diff --git a/main/samba/APKBUILD b/main/samba/APKBUILD
index 6c2f37b..4ffce24 100644
--- a/main/samba/APKBUILD
+++ b/main/samba/APKBUILD
@@ -1,7 +1,8 @@
+# Contributor: Sergei Lukin <[email-masked]>
 # Maintainer: Natanael Copa <[email-masked]>
 pkgname=samba
 pkgver=4.4.5
-pkgrel=1
+pkgrel=2
 pkgdesc="Tools to access a server's filespace and printers via SMB"
 url="http://www.samba.org"
 arch="all"
@@ -47,6 +48,7 @@ source="http://us1.samba.org/samba/ftp/stable/samba-$pkgver.tar.gz
 	uclibc-xattr-create.patch
 	domain.patch
 	getpwent_r.patch
+	samba-4.4.7-security-20016-12-19-CVE-2016-2123,CVE-2016-2125,CVE-2016-2126.patch
 
 	samba.initd
 	samba.confd
@@ -54,6 +56,12 @@ source="http://us1.samba.org/samba/ftp/stable/samba-$pkgver.tar.gz
 	"
 pkggroups="winbind"
 
+# secfixes:
+#   4.4.5-r2:
+#     - CVE-2016-2123
+#     - CVE-2016-2125
+#     - CVE-2016-2126
+
 _builddir="$srcdir"/samba-$pkgver
 prepare() {
 	cd "$_builddir"
@@ -512,6 +520,7 @@ md5sums="6950c5e9f7bdeb8a610c2ca957a15be4  samba-4.4.5.tar.gz
 f9ee1f13e59c60ee7e481f51329bf7d4  uclibc-xattr-create.patch
 f0d10a87a2067d0d3accdcb6c9b64ea9  domain.patch
 6a220b2471764e6e189829ac9cc81996  getpwent_r.patch
+29e6f401d2a71c42b24d1459b4633f9c  samba-4.4.7-security-20016-12-19-CVE-2016-2123,CVE-2016-2125,CVE-2016-2126.patch
 c1702b2ad7b68f7d704f50a1bfef3ad3  samba.initd
 c150433426e18261e6e3eed3930e1a76  samba.confd
 b7cafabfb4fa5b3ab5f2e857d8d1c733  samba.logrotate"
@@ -519,6 +528,7 @@ sha256sums="b876ef2e63f66265490e80a122e66ef2d7616112b839df68f56ac2e1ce17a7bd  sa
 dcf6a7118297d6567d8ff31c9eff1afffdf2f548db36fd17d00cdf0ffc555fe3  uclibc-xattr-create.patch
 5554fff0df5d31e67a705c60d97e187b4109c79c8a4063c8ea7ebe1e0e4a7e7e  domain.patch
 7956274b412a268339abb63f8e1bd63b5049cd4ab7c6270235d9d0b9bcf6c81a  getpwent_r.patch
+feedf1ccc311034252a5c7a2164a228e40f1244c3486d519aaf981ec9603ddb8  samba-4.4.7-security-20016-12-19-CVE-2016-2123,CVE-2016-2125,CVE-2016-2126.patch
 3866a15ab73a9fd704ec8315cff48caf98937c490ba8dc40ce3701cef5ca22c9  samba.initd
 1d12f98a7727967b04eb123109b34cfffef320822dc0e8059286b6e3394c3fc0  samba.confd
 4c2b7d529126b2fc4f62fb09d99e49a87632d723a2d9d289a61e37dd84145be1  samba.logrotate"
@@ -526,6 +536,7 @@ sha512sums="4e63fabbddc04ebdf08b68a98fe4fa0c525b30f7d949948dd5d2e5cba17d263db820
 b43809d7ecbf3968f5154c2ded6ed47dae36921f1895ea98bcce50557eb2ad39b736345ffb4214655ed3154c143c20431d248cde828285380bafbf4d2627df9b  uclibc-xattr-create.patch
 62d373dbaee75121a1d73f2c09cdca7239705808ff807b171d1d5a28fd4ffc66bdb52494b62786d7aaba8aeece5c08433b532ca96a28d712452fe9daac8d8d2e  domain.patch
 0d4fd9862191554dc9c724cec0b94fd19afbfd0c4ed619e4c620c075e849cb3f3d44db1e5f119d890da23a3dd0068d9873703f3d86c47b91310521f37356208b  getpwent_r.patch
+3b2b6c12a1e64f3c164153d51cd1286477eb89b8ee9093d63f9c819ebdf6b4cd0ae1553b119b0ca78cd81769925e66f24392d9e0254e0fe708b81d9a7ea62000  samba-4.4.7-security-20016-12-19-CVE-2016-2123,CVE-2016-2125,CVE-2016-2126.patch
 6bee83aab500f27248b315d8a5f567940d7232269b021d801b3d51c20ed9e4aad513ee0117f356fb388014a63a145beacb55307ef9addbf7997987304b548fcf  samba.initd
 4faf581ecef3ec38319e3c4ab6d3995c51fd7ba83180dc5553a2ff4dfb92efadb43030c543292130c4ed0c281dc0972c6973d52d48062c5edb39bb1c4bbb6dd6  samba.confd
 f88ebe59ca3a9e9b77dd5993c13ef3e73a838efb8ed858088b464a330132d662f33e25c27819e38835389dee23057a3951de11bae1eef55db8ff5e1ec6760053  samba.logrotate"
diff --git a/main/samba/samba-4.4.7-security-20016-12-19-CVE-2016-2123,CVE-2016-2125,CVE-2016-2126.patch b/main/samba/samba-4.4.7-security-20016-12-19-CVE-2016-2123,CVE-2016-2125,CVE-2016-2126.patch
new file mode 100644
index 0000000..79e67e6
--- /dev/null
+++ b/main/samba/samba-4.4.7-security-20016-12-19-CVE-2016-2123,CVE-2016-2125,CVE-2016-2126.patch
@@ -0,0 +1,200 @@
+From 4aa6b11d64a0a8133ef39a7e626f289f769e9415 Mon Sep 17 00:00:00 2001
+From: Volker Lendecke <[email-masked]>
+Date: Sat, 5 Nov 2016 21:22:46 +0100
+Subject: [PATCH 1/5] CVE-2016-2123: Fix DNS vuln ZDI-CAN-3995
+
+Thanks to Trend Micro's Zero Day Initiative and Frederic Besler for finding
+this vulnerability with a PoC and a good analysis.
+
+Signed-off-by: Volker Lendecke <[email-masked]>
+Bug: https://bugzilla.samba.org/show_bug.cgi?id=12409
+---
+ librpc/ndr/ndr_dnsp.c | 9 +++++++++
+ 1 file changed, 9 insertions(+)
+
+diff --git a/librpc/ndr/ndr_dnsp.c b/librpc/ndr/ndr_dnsp.c
+index 3cb96f9..0541261 100644
+--- a/librpc/ndr/ndr_dnsp.c
++++ b/librpc/ndr/ndr_dnsp.c
+@@ -56,7 +56,16 @@ _PUBLIC_ enum ndr_err_code ndr_pull_dnsp_name(struct ndr_pull *ndr, int ndr_flag
+ 		uint8_t sublen, newlen;
+ 		NDR_CHECK(ndr_pull_uint8(ndr, ndr_flags, &sublen));
+ 		newlen = total_len + sublen;
++		if (newlen < total_len) {
++			return ndr_pull_error(ndr, NDR_ERR_RANGE,
++					      "Failed to pull dnsp_name");
++		}
+ 		if (i != count-1) {
++			if (newlen == UINT8_MAX) {
++				return ndr_pull_error(
++					ndr, NDR_ERR_RANGE,
++					"Failed to pull dnsp_name");
++			}
+ 			newlen++; /* for the '.' */
+ 		}
+ 		ret = talloc_realloc(ndr->current_mem_ctx, ret, char, newlen);
+-- 
+1.9.1
+
+
+From 0f1b36b7d5514f8d16c60ebcd5c59753113b4334 Mon Sep 17 00:00:00 2001
+From: Stefan Metzmacher <[email-masked]>
+Date: Wed, 23 Nov 2016 11:41:10 +0100
+Subject: [PATCH 2/5] CVE-2016-2125: s4:scripting: don't use GSS_C_DELEG_FLAG
+ in nsupdate-gss
+
+This is just an example script that's not directly used by samba,
+but we should avoid sending delegated credentials to dns servers.
+
+BUG: https://bugzilla.samba.org/show_bug.cgi?id=12445
+
+Signed-off-by: Stefan Metzmacher <[email-masked]>
+Reviewed-by: Alexander Bokovoy <[email-masked]>
+Reviewed-by: Simo Sorce <[email-masked]>
+---
+ source4/scripting/bin/nsupdate-gss | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/source4/scripting/bin/nsupdate-gss b/source4/scripting/bin/nsupdate-gss
+index dec5916..509220d 100755
+--- a/source4/scripting/bin/nsupdate-gss
++++ b/source4/scripting/bin/nsupdate-gss
+@@ -178,7 +178,7 @@ sub negotiate_tkey($$$$)
+     my $flags = 
+ 	GSS_C_REPLAY_FLAG | GSS_C_MUTUAL_FLAG | 
+ 	GSS_C_SEQUENCE_FLAG | GSS_C_CONF_FLAG | 
+-	GSS_C_INTEG_FLAG | GSS_C_DELEG_FLAG;
++	GSS_C_INTEG_FLAG;
+ 
+ 
+     $status = GSSAPI::Cred::acquire_cred(undef, 120, undef, GSS_C_INITIATE,
+-- 
+1.9.1
+
+
+From 07ef0f6ce0fb9d9735710ab79c2ee91d7a72a974 Mon Sep 17 00:00:00 2001
+From: Stefan Metzmacher <[email-masked]>
+Date: Wed, 23 Nov 2016 11:42:59 +0100
+Subject: [PATCH 3/5] CVE-2016-2125: s3:gse: avoid using GSS_C_DELEG_FLAG
+
+We should only use GSS_C_DELEG_POLICY_FLAG in order to let
+the KDC decide if we should send delegated credentials to
+a remote server.
+
+BUG: https://bugzilla.samba.org/show_bug.cgi?id=12445
+
+Signed-off-by: Stefan Metzmacher <[email-masked]>
+Reviewed-by: Alexander Bokovoy <[email-masked]>
+Reviewed-by: Simo Sorce <[email-masked]>
+---
+ source3/librpc/crypto/gse.c | 1 -
+ 1 file changed, 1 deletion(-)
+
+diff --git a/source3/librpc/crypto/gse.c b/source3/librpc/crypto/gse.c
+index 963c98a..c4c4bbc 100644
+--- a/source3/librpc/crypto/gse.c
++++ b/source3/librpc/crypto/gse.c
+@@ -142,7 +142,6 @@ static NTSTATUS gse_context_init(TALLOC_CTX *mem_ctx,
+ 	memcpy(&gse_ctx->gss_mech, gss_mech_krb5, sizeof(gss_OID_desc));
+ 
+ 	gse_ctx->gss_want_flags = GSS_C_MUTUAL_FLAG |
+-				GSS_C_DELEG_FLAG |
+ 				GSS_C_DELEG_POLICY_FLAG |
+ 				GSS_C_REPLAY_FLAG |
+ 				GSS_C_SEQUENCE_FLAG;
+-- 
+1.9.1
+
+
+From 58586ceae7fe628453e6bffdc463d4309ced15fb Mon Sep 17 00:00:00 2001
+From: Stefan Metzmacher <[email-masked]>
+Date: Wed, 23 Nov 2016 11:44:22 +0100
+Subject: [PATCH 4/5] CVE-2016-2125: s4:gensec_gssapi: don't use
+ GSS_C_DELEG_FLAG by default
+
+This disabled the usage of GSS_C_DELEG_FLAG by default, as
+GSS_C_DELEG_POLICY_FLAG is still used by default we let the
+KDC decide if we should send delegated credentials to a remote server.
+
+BUG: https://bugzilla.samba.org/show_bug.cgi?id=12445
+
+Signed-off-by: Stefan Metzmacher <[email-masked]>
+Reviewed-by: Alexander Bokovoy <[email-masked]>
+Reviewed-by: Simo Sorce <[email-masked]>
+---
+ source4/auth/gensec/gensec_gssapi.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/source4/auth/gensec/gensec_gssapi.c b/source4/auth/gensec/gensec_gssapi.c
+index e0b2bf2..e2994f6 100644
+--- a/source4/auth/gensec/gensec_gssapi.c
++++ b/source4/auth/gensec/gensec_gssapi.c
+@@ -115,7 +115,7 @@ static NTSTATUS gensec_gssapi_start(struct gensec_security *gensec_security)
+ 	if (gensec_setting_bool(gensec_security->settings, "gensec_gssapi", "mutual", true)) {
+ 		gensec_gssapi_state->gss_want_flags |= GSS_C_MUTUAL_FLAG;
+ 	}
+-	if (gensec_setting_bool(gensec_security->settings, "gensec_gssapi", "delegation", true)) {
++	if (gensec_setting_bool(gensec_security->settings, "gensec_gssapi", "delegation", false)) {
+ 		gensec_gssapi_state->gss_want_flags |= GSS_C_DELEG_FLAG;
+ 	}
+ 	if (gensec_setting_bool(gensec_security->settings, "gensec_gssapi", "replay", true)) {
+-- 
+1.9.1
+
+
+From ce31a69a32d2bd6975006e428afe4584f6b7bc43 Mon Sep 17 00:00:00 2001
+From: Stefan Metzmacher <[email-masked]>
+Date: Tue, 22 Nov 2016 17:08:46 +0100
+Subject: [PATCH 5/5] CVE-2016-2126: auth/kerberos: only allow known checksum
+ types in check_pac_checksum()
+
+aes based checksums can only be checked with the
+corresponding aes based keytype.
+
+Otherwise we may trigger an undefined code path
+deep in the kerberos libraries, which can leed to
+segmentation faults.
+
+BUG: https://bugzilla.samba.org/show_bug.cgi?id=12446
+
+Signed-off-by: Stefan Metzmacher <[email-masked]>
+---
+ auth/kerberos/kerberos_pac.c | 22 ++++++++++++++++++++++
+ 1 file changed, 22 insertions(+)
+
+diff --git a/auth/kerberos/kerberos_pac.c b/auth/kerberos/kerberos_pac.c
+index 32d9d7f..7b6efdc 100644
+--- a/auth/kerberos/kerberos_pac.c
++++ b/auth/kerberos/kerberos_pac.c
+@@ -39,6 +39,28 @@ krb5_error_code check_pac_checksum(DATA_BLOB pac_data,
+ 	krb5_boolean checksum_valid = false;
+ 	krb5_data input;
+ 
++	switch (sig->type) {
++	case CKSUMTYPE_HMAC_MD5:
++		/* ignores the key type */
++		break;
++	case CKSUMTYPE_HMAC_SHA1_96_AES_256:
++		if (KRB5_KEY_TYPE(keyblock) != ENCTYPE_AES256_CTS_HMAC_SHA1_96) {
++			return EINVAL;
++		}
++		/* ok */
++		break;
++	case CKSUMTYPE_HMAC_SHA1_96_AES_128:
++		if (KRB5_KEY_TYPE(keyblock) != ENCTYPE_AES128_CTS_HMAC_SHA1_96) {
++			return EINVAL;
++		}
++		/* ok */
++		break;
++	default:
++		DEBUG(2,("check_pac_checksum: Checksum Type %d is not supported\n",
++			(int)sig->type));
++		return EINVAL;
++	}
++
+ #ifdef HAVE_CHECKSUM_IN_KRB5_CHECKSUM /* Heimdal */
+ 	cksum.cksumtype	= (krb5_cksumtype)sig->type;
+ 	cksum.checksum.length	= sig->signature.length;
+-- 
+1.9.1
+
-- 
2.8.3

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