diff --git a/postfix/HISTORY b/postfix/HISTORY
index 1c0c5eac3..0f55b7bd1 100644
--- a/postfix/HISTORY
+++ b/postfix/HISTORY
@@ -23021,15 +23021,12 @@ Apologies for any names omitted.
 
 20170611
 
-	Security: Berkeley DB 2 and later have an undocumented
-	feature that tries to read instructions from a file DB_CONFIG
-	in the current directory. This may expose Postfix set-gid
-	programs (postdrop, postqueue) to attacks before they chdir
-	to the Postfix queue directory, and the postmap and postalias
-	commands depending on whether the user's current directory
-	is writable by other users. This fix does not change Postfix
-	behavior for Berkeley DB < 3. It makes the berkeley_db_buffer_size
-	and berkeley_db_create_buffer_size parameters obsolete for
-	Berkeley DB 3 and later, because they appear to have no API
-	to find out the maximal cache size they would accept. Postmap
-	create operations will be about 3x slower. File: util/dict_db.c.
+	Security: Berkeley DB 2 and later try to read settings from
+	a file DB_CONFIG in the current directory.  This undocumented
+	feature may introduce undisclosed vulnerabilities resulting in
+	privilege escalation with Postfix set-gid programs (postdrop,
+	postqueue) before they chdir to the Postfix queue directory,
+	and with the postmap and postalias commands depending on whether
+	the user's current directory is writable by other users. This
+	fix does not change Postfix behavior for Berkeley DB < 3.
+	File: util/dict_db.c.
diff --git a/postfix/src/global/mail_params.c b/postfix/src/global/mail_params.c
index ece9ec071..adee25848 100644
--- a/postfix/src/global/mail_params.c
+++ b/postfix/src/global/mail_params.c
@@ -881,6 +881,7 @@ void    mail_params_init()
     check_sgid_group();
     check_overlap();
     dict_db_cache_size = var_db_read_buf;
+    dict_db_home = mystrdup(var_config_dir);
     dict_lmdb_map_size = var_lmdb_map_size;
     inet_windowsize = var_inet_windowsize;
 
diff --git a/postfix/src/global/mail_version.h b/postfix/src/global/mail_version.h
index 9a5bc87e7..bd7b1b29b 100644
--- a/postfix/src/global/mail_version.h
+++ b/postfix/src/global/mail_version.h
@@ -20,7 +20,7 @@
   * Patches change both the patchlevel and the release date. Snapshots have no
   * patchlevel; they change the release date only.
   */
-#define MAIL_RELEASE_DATE	"20170611"
+#define MAIL_RELEASE_DATE	"20170612"
 #define MAIL_VERSION_NUMBER	"3.3"
 
 #ifdef SNAPSHOT
diff --git a/postfix/src/util/dict_db.c b/postfix/src/util/dict_db.c
index 7671bbeed..5dc91738e 100644
--- a/postfix/src/util/dict_db.c
+++ b/postfix/src/util/dict_db.c
@@ -7,6 +7,7 @@
 /*	#include <dict_db.h>
 /*
 /*	extern int dict_db_cache_size;
+/*	extern char *dict_db_home;
 /*
 /*	DEFINE_DICT_DB_CACHE_SIZE;
 /*
@@ -33,6 +34,9 @@
 /*	must therefore be defined in the calling program by invoking
 /*	the DEFINE_DICT_DB_CACHE_SIZE macro at the global level.
 /*
+/*	dict_db_home specifies the default location of the DB_CONFIG
+/*	file with configuration overrides.
+/*
 /*	Arguments:
 /* .IP path
 /*	The database pathname, not including the ".db" suffix.
@@ -586,7 +590,9 @@ static DICT *dict_db_open(const char *class, const char *path, int open_flags,
 #endif
 #if DB_VERSION_MAJOR > 2
     DB_ENV *dbenv;
-    VSTRING *dirname_buf;
+    u_int32_t cache_size_gbytes;
+    u_int32_t cache_size_bytes;
+    int     ncache;
 
 #endif
 
@@ -692,14 +698,28 @@ static DICT *dict_db_open(const char *class, const char *path, int open_flags,
 	db_flags |= DB_CREATE;
     if (open_flags & O_TRUNC)
 	db_flags |= DB_TRUNCATE;
-    /* Fix 20170611 workaround for undocumented ./DB_CONFIG read. */
+    /* Begin fix 20170611 workaround for undocumented ./DB_CONFIG read. */
     if ((errno = db_env_create(&dbenv, 0)) != 0)
 	msg_fatal("create DB environment: %m");
-    dirname_buf = vstring_alloc(100);
-    if ((errno = dbenv->open(dbenv, sane_dirname(dirname_buf, db_path),
+#if DB_VERSION_MAJOR > 4 || (DB_VERSION_MAJOR == 4 && DB_VERSION_MINOR >= 7)
+    /* Begin fix 20170612 workaround for invisible cache size limit. */
+    if ((errno = dbenv->get_cachesize(dbenv, &cache_size_gbytes,
+				      &cache_size_bytes, &ncache)) != 0)
+	msg_fatal("get DB cache size: %m");
+    if (cache_size_gbytes == 0 && cache_size_bytes < dict_db_cache_size) {
+	if ((errno = dbenv->set_cache_max(dbenv, cache_size_gbytes,
+					  dict_db_cache_size)) != 0)
+	    msg_fatal("set DB max cache size %d: %m", dict_db_cache_size);
+	if ((errno = dbenv->set_cachesize(dbenv, cache_size_gbytes,
+					  dict_db_cache_size, ncache)) != 0)
+	    msg_fatal("set DB cache size %d: %m", dict_db_cache_size);
+    }
+    /* End fix 20170612 workaround for invisible cache size limit. */
+#endif
+    if ((errno = dbenv->open(dbenv, dict_db_home,
 			   DB_INIT_MPOOL | DB_CREATE | DB_PRIVATE, 0)) != 0)
 	msg_fatal("open DB environment: %m");
-    vstring_free(dirname_buf);
+    /* End fix 20170611 workaround for undocumented ./DB_CONFIG read. */
     if ((errno = db_create(&db, dbenv, 0)) != 0)
 	msg_fatal("create DB database: %m");
     if (db == 0)
diff --git a/postfix/src/util/dict_db.h b/postfix/src/util/dict_db.h
index 9b5f6cada..862685332 100644
--- a/postfix/src/util/dict_db.h
+++ b/postfix/src/util/dict_db.h
@@ -33,8 +33,10 @@ extern DICT *dict_btree_open(const char *, int, int);
   * set a larger memory pool for database (re)builds.
   */
 extern int dict_db_cache_size;
+extern char *dict_db_home;
 
 #define DEFINE_DICT_DB_CACHE_SIZE int dict_db_cache_size = (128 * 1024)
+#define DEFINE_DICT_DB_HOME char *dict_db_home = "/"
 
 /* LICENSE
 /* .ad
diff --git a/postfix/src/util/dict_open.c b/postfix/src/util/dict_open.c
index bc33174ea..8328296a5 100644
--- a/postfix/src/util/dict_open.c
+++ b/postfix/src/util/dict_open.c
@@ -395,6 +395,7 @@ static DICT_MAPNAMES_EXTEND_FN dict_mapnames_extend_hook;
   */
 DEFINE_DICT_LMDB_MAP_SIZE;
 DEFINE_DICT_DB_CACHE_SIZE;
+DEFINE_DICT_DB_HOME;
 
 /* dict_open_init - one-off initialization */