diff --git a/lib/typo3/class.t3lib_cs.php b/lib/typo3/class.t3lib_cs.php
index 00dfc697250..ad1a6409fcd 100644
--- a/lib/typo3/class.t3lib_cs.php
+++ b/lib/typo3/class.t3lib_cs.php
@@ -679,7 +679,7 @@ class t3lib_cs {
 				$chr = substr($str, $a, 1);
 				$ord = ord($chr);
 				if (isset($this->twoByteSets[$charset])) { // If the charset has two bytes per char
-					$ord2 = ord($str{$a + 1});
+					$ord2 = ord($str[$a + 1]);
 					$ord = $ord << 8 | $ord2; // assume big endian
 
 					if (isset($this->parsedCharsets[$charset]['local'][$ord])) { // If the local char-number was found in parsed conv. table then we use that, otherwise 127 (no char?)
@@ -1164,7 +1164,7 @@ class t3lib_cs {
 				$utf8CaseFolding['toTitle'][$utf8_char] = $this->UnumberToChar(hexdec($title));
 			}
 
-			switch ($cat{0}) {
+			switch ($cat[0]) {
 				case 'M': // mark (accent, umlaut, ...)
 					$mark["U+$char"] = 1;
 					break;
@@ -1224,10 +1224,10 @@ class t3lib_cs {
 			if ($fh) {
 				while (!feof($fh)) {
 					$line = fgets($fh, 4096);
-					if ($line{0} != '#' && trim($line) != '') {
+					if ($line[0] != '#' && trim($line) != '') {
 
 						list($char, $lower, $title, $upper, $cond) = t3lib_div::trimExplode(';', $line);
-						if ($cond == '' || $cond{0} == '#') {
+						if ($cond == '' || $cond[0] == '#') {
 							$utf8_char = $this->UnumberToChar(hexdec($char));
 							if ($char != $lower) {
 								$arr = explode(' ', $lower);
@@ -1264,7 +1264,7 @@ class t3lib_cs {
 			if ($fh) {
 				while (!feof($fh)) {
 					$line = fgets($fh, 4096);
-					if ($line{0} != '#' && trim($line) != '') {
+					if ($line[0] != '#' && trim($line) != '') {
 						list($char, $translit) = t3lib_div::trimExplode(';', $line);
 						if (!$translit) {
 							$omit["U+$char"] = 1;
@@ -1609,12 +1609,12 @@ class t3lib_cs {
 			return $string;
 		} else {
 			if ($len > 0) {
-				if (strlen($string{$i})) {
+				if (strlen($string[$i])) {
 					return substr($string, 0, $i) . $crop;
 
 				}
 			} else {
-				if (strlen($string{$i - 1})) {
+				if (strlen($string[$i - 1])) {
 					return $crop . substr($string, $i);
 				}
 			}
@@ -1835,8 +1835,8 @@ class t3lib_cs {
 		}
 
 		$out = '';
-		for ($i = 0; strlen($str{$i}); $i++) {
-			$c = $str{$i};
+		for ($i = 0; strlen($str[$i]); $i++) {
+			$c = $str[$i];
 			if (isset($map[$c])) {
 				$out .= $map[$c];
 			} else {
@@ -1908,8 +1908,8 @@ class t3lib_cs {
 	 */
 	function utf8_strlen($str) {
 		$n = 0;
-		for ($i = 0; strlen($str{$i}); $i++) {
-			$c = ord($str{$i});
+		for ($i = 0; strlen($str[$i]); $i++) {
+			$c = ord($str[$i]);
 			if (!($c & 0x80)) // single-byte (0xxxxxx)
 			{
 				$n++;
@@ -1933,15 +1933,15 @@ class t3lib_cs {
 	 */
 	function utf8_strtrunc($str, $len) {
 		$i = $len - 1;
-		if (ord($str{$i}) & 0x80) { // part of a multibyte sequence
-			for (; $i > 0 && !(ord($str{$i}) & 0x40); $i--) {
+		if (ord($str[$i]) & 0x80) { // part of a multibyte sequence
+			for (; $i > 0 && !(ord($str[$i]) & 0x40); $i--) {
 				// find the first byte
 				;
 			}
 			if ($i <= 0) {
 				return '';
 			} // sanity check
-			for ($bc = 0, $mbs = ord($str{$i}); $mbs & 0x80; $mbs = $mbs << 1) {
+			for ($bc = 0, $mbs = ord($str[$i]); $mbs & 0x80; $mbs = $mbs << 1) {
 				// calculate number of bytes
 				$bc++;
 			}
@@ -2028,8 +2028,8 @@ class t3lib_cs {
 			$d = -1;
 		}
 
-		for (; strlen($str{$i}) && $n < $p; $i += $d) {
-			$c = (int) ord($str{$i});
+		for (; strlen($str[$i]) && $n < $p; $i += $d) {
+			$c = (int) ord($str[$i]);
 			if (!($c & 0x80)) // single-byte (0xxxxxx)
 			{
 				$n++;
@@ -2039,13 +2039,13 @@ class t3lib_cs {
 				$n++;
 			}
 		}
-		if (!strlen($str{$i})) {
+		if (!strlen($str[$i])) {
 			return FALSE;
 		} // offset beyond string length
 
 		if ($pos >= 0) {
 				// skip trailing multi-byte data bytes
-			while ((ord($str{$i}) & 0x80) && !(ord($str{$i}) & 0x40)) {
+			while ((ord($str[$i]) & 0x80) && !(ord($str[$i]) & 0x40)) {
 				$i++;
 			}
 		} else {
@@ -2068,7 +2068,7 @@ class t3lib_cs {
 	function utf8_byte2char_pos($str, $pos) {
 		$n = 0; // number of characters
 		for ($i = $pos; $i > 0; $i--) {
-			$c = (int) ord($str{$i});
+			$c = (int) ord($str[$i]);
 			if (!($c & 0x80)) // single-byte (0xxxxxx)
 			{
 				$n++;
@@ -2078,7 +2078,7 @@ class t3lib_cs {
 				$n++;
 			}
 		}
-		if (!strlen($str{$i})) {
+		if (!strlen($str[$i])) {
 			return FALSE;
 		} // offset beyond string length
 
@@ -2113,11 +2113,11 @@ class t3lib_cs {
 				return $str;
 		}
 
-		for ($i = 0; strlen($str{$i}); $i++) {
-			$c = ord($str{$i});
+		for ($i = 0; strlen($str[$i]); $i++) {
+			$c = ord($str[$i]);
 			if (!($c & 0x80)) // single-byte (0xxxxxx)
 			{
-				$mbc = $str{$i};
+				$mbc = $str[$i];
 			}
 			elseif (($c & 0xC0) == 0xC0) { // multi-byte starting byte (11xxxxxx)
 				for ($bc = 0; $c & 0x80; $c = $c << 1) {
@@ -2162,8 +2162,8 @@ class t3lib_cs {
 	 */
 	function euc_strtrunc($str, $len, $charset) {
 		$sjis = ($charset == 'shift_jis');
-		for ($i = 0; strlen($str{$i}) && $i < $len; $i++) {
-			$c = ord($str{$i});
+		for ($i = 0; strlen($str[$i]) && $i < $len; $i++) {
+			$c = ord($str[$i]);
 			if ($sjis) {
 				if (($c >= 0x80 && $c < 0xA0) || ($c >= 0xE0)) {
 					$i++;
@@ -2175,7 +2175,7 @@ class t3lib_cs {
 				} // advance a double-byte char
 			}
 		}
-		if (!strlen($str{$i})) {
+		if (!strlen($str[$i])) {
 			return $str;
 		} // string shorter than supplied length
 
@@ -2232,8 +2232,8 @@ class t3lib_cs {
 	function euc_strlen($str, $charset) {
 		$sjis = ($charset == 'shift_jis');
 		$n = 0;
-		for ($i = 0; strlen($str{$i}); $i++) {
-			$c = ord($str{$i});
+		for ($i = 0; strlen($str[$i]); $i++) {
+			$c = ord($str[$i]);
 			if ($sjis) {
 				if (($c >= 0x80 && $c < 0xA0) || ($c >= 0xE0)) {
 					$i++;
@@ -2273,8 +2273,8 @@ class t3lib_cs {
 			$d = -1;
 		}
 
-		for (; strlen($str{$i}) && $n < $p; $i += $d) {
-			$c = ord($str{$i});
+		for (; strlen($str[$i]) && $n < $p; $i += $d) {
+			$c = ord($str[$i]);
 			if ($sjis) {
 				if (($c >= 0x80 && $c < 0xA0) || ($c >= 0xE0)) {
 					$i += $d;
@@ -2288,7 +2288,7 @@ class t3lib_cs {
 
 			$n++;
 		}
-		if (!strlen($str{$i})) {
+		if (!strlen($str[$i])) {
 			return FALSE;
 		} // offset beyond string length
 
@@ -2331,8 +2331,8 @@ class t3lib_cs {
 
 		$sjis = ($charset == 'shift_jis');
 		$out = '';
-		for ($i = 0; strlen($str{$i}); $i++) {
-			$mbc = $str{$i};
+		for ($i = 0; strlen($str[$i]); $i++) {
+			$mbc = $str[$i];
 			$c = ord($mbc);
 
 			if ($sjis) {
diff --git a/lib/typo3/class.t3lib_div.php b/lib/typo3/class.t3lib_div.php
index 243db4d9e87..ad761763f0d 100644
--- a/lib/typo3/class.t3lib_div.php
+++ b/lib/typo3/class.t3lib_div.php
@@ -1363,7 +1363,7 @@ final class t3lib_div {
 		$bytesToGenerate = max(4096, $bytesToReturn);
 
 			// if we have not enough random bytes cached, we generate new ones
-		if (!isset($bytes{$bytesToReturn - 1})) {
+		if (!isset($bytes[$bytesToReturn - 1])) {
 			if (TYPO3_OS === 'WIN') {
 					// Openssl seems to be deadly slow on Windows, so try to use mcrypt
 					// Windows PHP versions have a bug when using urandom source (see #24410)
@@ -1372,18 +1372,18 @@ final class t3lib_div {
 					// Try to use native PHP functions first, precedence has openssl
 				$bytes .= self::generateRandomBytesOpenSsl($bytesToGenerate);
 
-				if (!isset($bytes{$bytesToReturn - 1})) {
+				if (!isset($bytes[$bytesToReturn - 1])) {
 					$bytes .= self::generateRandomBytesMcrypt($bytesToGenerate, MCRYPT_DEV_URANDOM);
 				}
 
 					// If openssl and mcrypt failed, try /dev/urandom
-				if (!isset($bytes{$bytesToReturn - 1})) {
+				if (!isset($bytes[$bytesToReturn - 1])) {
 					$bytes .= self::generateRandomBytesUrandom($bytesToGenerate);
 				}
 			}
 
 				// Fall back if other random byte generation failed until now
-			if (!isset($bytes{$bytesToReturn - 1})) {
+			if (!isset($bytes[$bytesToReturn - 1])) {
 				$bytes .= self::generateRandomBytesFallback($bytesToReturn);
 			}
 		}
@@ -1453,7 +1453,7 @@ final class t3lib_div {
 		$bytes = '';
 			// We initialize with somewhat random.
 		$randomState = $GLOBALS['TYPO3_CONF_VARS']['SYS']['encryptionKey'] . base_convert(memory_get_usage() % pow(10, 6), 10, 2) . microtime() . uniqid('') . getmypid();
-		while (!isset($bytes{$bytesToReturn - 1})) {
+		while (!isset($bytes[$bytesToReturn - 1])) {
 			$randomState = sha1(microtime() . mt_rand() . $randomState);
 			$bytes .= sha1(mt_rand() . $randomState, TRUE);
 		}
@@ -5318,7 +5318,7 @@ final class t3lib_div {
 		$matches = preg_split('/(.?###.+###.?|\(|\))/', $line, -1, PREG_SPLIT_NO_EMPTY);
 		foreach ($matches as $part) {
 			$oldPart = $part;
-			$partWasQuoted = ($part{0} == '"');
+			$partWasQuoted = ($part[0] == '"');
 			$part = trim($part, '"');
 			switch ((string) $enc) {
 				case 'base64':
diff --git a/lib/typo3/readme_moodle.txt b/lib/typo3/readme_moodle.txt
index cb1e332561b..ad6bf1c38c8 100644
--- a/lib/typo3/readme_moodle.txt
+++ b/lib/typo3/readme_moodle.txt
@@ -10,6 +10,11 @@ Procedure:
 
 Local changes (to verify/apply with new imports):
 
+- MDL-67017: PHP 7.4 compatibility. Curly brackets.
+    Remove all the deprecated curly bracket uses {} to access to strings/arrays
+    by key. We haven't looked how this is fixed upstream because plans include
+    to remove this library from core (see MDL-65809)
+
 - MDL-63967: PHP 7.3 compatibility.
     lib/typo3/class.t3lib_div.php: FILTER_FLAG_SCHEME_REQUIRED is deprecated and
     implied with FILTER_VALIDATE_URL. This is fixed upstream since Typo 6, with