diff -Nru nss-3.28.4/debian/changelog nss-3.28.4/debian/changelog
--- nss-3.28.4/debian/changelog	2017-06-16 12:13:46.000000000 +0000
+++ nss-3.28.4/debian/changelog	2017-09-29 12:54:11.000000000 +0000
@@ -1,3 +1,12 @@
+nss (2:3.28.4-0ubuntu0.16.04.3) xenial-security; urgency=medium
+
+  * SECURITY UPDATE: Use-after-free in TLS 1.2 generating handshake hashes
+    - debian/patches/CVE-2017-7805.patch: Simplify handling of
+      CertificateVerify in nss/lib/ssl/ssl3con.c, nss/lib/ssl/ssl3prot.h.
+    - CVE-2017-7805
+
+ -- Marc Deslauriers <marc.deslauriers@ubuntu.com>  Fri, 29 Sep 2017 08:54:11 -0400
+
 nss (2:3.28.4-0ubuntu0.16.04.2) xenial-security; urgency=medium
 
   * SECURITY UPDATE: DoS via empty SSLv2 messages
diff -Nru nss-3.28.4/debian/patches/CVE-2017-7805.patch nss-3.28.4/debian/patches/CVE-2017-7805.patch
--- nss-3.28.4/debian/patches/CVE-2017-7805.patch	1970-01-01 00:00:00.000000000 +0000
+++ nss-3.28.4/debian/patches/CVE-2017-7805.patch	2017-09-29 12:54:07.000000000 +0000
@@ -0,0 +1,66 @@
+Backport of:
+
+# HG changeset patch
+# User Martin Thomson <martin.thomson@gmail.com>
+# Date 1501813647 -36000
+# Node ID 839200ce0943166a079284bdf45dcc37bb672925
+# Parent  6254e8431392863fd0aa7e70c311add48af05775
+Bug 1377618 - Simplify handling of CertificateVerify, r=kaie
+
+Index: nss-3.28.4/nss/lib/ssl/ssl3con.c
+===================================================================
+--- nss-3.28.4.orig/nss/lib/ssl/ssl3con.c	2017-09-29 08:50:13.360518595 -0400
++++ nss-3.28.4/nss/lib/ssl/ssl3con.c	2017-09-29 08:50:13.356518549 -0400
+@@ -9774,13 +9774,12 @@ ssl3_HandleCertificateVerify(sslSocket *
+ 
+         hashAlg = ssl_SignatureSchemeToHashType(sigScheme);
+ 
+-        if (hashes->u.pointer_to_hash_input.data) {
+-            rv = ssl3_ComputeHandshakeHash(hashes->u.pointer_to_hash_input.data,
+-                                           hashes->u.pointer_to_hash_input.len,
+-                                           hashAlg, &localHashes);
+-        } else {
+-            rv = SECFailure;
+-        }
++        /* Read from the message buffer, but we need to use only up to the end
++         * of the previous handshake message. The length of the transcript up to
++         * that point is saved in |hashes->u.transcriptLen|. */
++        rv = ssl3_ComputeHandshakeHash(ss->ssl3.hs.messages.buf,
++                                       hashes->u.transcriptLen,
++                                       hashAlg, &localHashes);
+ 
+         if (rv == SECSuccess) {
+             hashesForVerify = &localHashes;
+@@ -11680,15 +11679,15 @@ ssl3_HandleHandshakeMessage(sslSocket *s
+                  * additional handshake messages will have been added to the
+                  * buffer, e.g. the certificate_verify message itself.)
+                  *
+-                 * Therefore, we use SSL3Hashes.u.pointer_to_hash_input
+-                 * to signal the current state of the buffer.
++                 * Therefore, we use SSL3Hashes.u.transcriptLen to save how much
++                 * data there is and read directly from ss->ssl3.hs.messages
++                 * when calculating the hashes.
+                  *
+                  * ssl3_HandleCertificateVerify will detect
+                  *     hashType == handshake_hash_record
+                  * and use that information to calculate the hash.
+                  */
+-                hashes.u.pointer_to_hash_input.data = ss->ssl3.hs.messages.buf;
+-                hashes.u.pointer_to_hash_input.len = ss->ssl3.hs.messages.len;
++                hashes.u.transcriptLen = ss->ssl3.hs.messages.len;
+                 hashesPtr = &hashes;
+             } else {
+                 computeHashes = PR_TRUE;
+Index: nss-3.28.4/nss/lib/ssl/ssl3prot.h
+===================================================================
+--- nss-3.28.4.orig/nss/lib/ssl/ssl3prot.h	2017-09-29 08:50:13.360518595 -0400
++++ nss-3.28.4/nss/lib/ssl/ssl3prot.h	2017-09-29 08:50:42.164845265 -0400
+@@ -237,7 +237,7 @@ typedef struct {
+     union {
+         PRUint8 raw[64];
+         SSL3HashesIndividually s;
+-        SECItem pointer_to_hash_input;
++        unsigned int transcriptLen;
+     } u;
+ } SSL3Hashes;
+ 
diff -Nru nss-3.28.4/debian/patches/series nss-3.28.4/debian/patches/series
--- nss-3.28.4/debian/patches/series	2017-06-16 12:13:39.000000000 +0000
+++ nss-3.28.4/debian/patches/series	2017-09-29 12:54:07.000000000 +0000
@@ -3,3 +3,4 @@
 80_security_tools.patch
 85_security_load.patch
 CVE-2017-7502.patch
+CVE-2017-7805.patch