diff --git a/lib/ftp.c b/lib/ftp.c
index a799c53279..d93d2d9ff4 100644
--- a/lib/ftp.c
+++ b/lib/ftp.c
@@ -2489,24 +2489,27 @@ static CURLcode ftp_state_port_resp(struct Curl_easy *data,
   return result;
 }
 
-static int twodigit(const char *p)
+/* return TRUE on error, FALSE on success */
+static bool twodigit(const char *p, int *val)
 {
-  return ((p[0] - '0') * 10) + (p[1] - '0');
+  if(!ISDIGIT(p[0]) || !ISDIGIT(p[1]))
+    return TRUE;
+  /* curlx_hexval() works fine here since we make sure it is decimal above */
+  *val = (curlx_hexval(p[0]) * 10) + curlx_hexval(p[1]);
+  return FALSE;
 }
 
 static bool ftp_213_date(const char *p, int *year, int *month, int *day,
                          int *hour, int *minute, int *second)
 {
-  size_t len = strlen(p);
-  if(len < 14)
+  int century;
+  if((strlen(p) < 14) || twodigit(&p[0], &century) || twodigit(&p[2], year) ||
+     twodigit(&p[4], month) || twodigit(&p[6], day) ||
+     twodigit(&p[8], hour) || twodigit(&p[10], minute) ||
+     twodigit(&p[12], second))
     return FALSE;
-  *year = (twodigit(&p[0]) * 100) + twodigit(&p[2]);
-  *month = twodigit(&p[4]);
-  *day = twodigit(&p[6]);
-  *hour = twodigit(&p[8]);
-  *minute = twodigit(&p[10]);
-  *second = twodigit(&p[12]);
 
+  *year += century * 100;
   if((*month > 12) || (*day > 31) || (*hour > 23) || (*minute > 59) ||
      (*second > 60))
     return FALSE;
diff --git a/tests/data/Makefile.am b/tests/data/Makefile.am
index 34eb547d9c..f8d8548265 100644
--- a/tests/data/Makefile.am
+++ b/tests/data/Makefile.am
@@ -226,7 +226,7 @@ test1666 test1667 \
 \
 test1670 test1671 \
 \
-test1680 test1681 test1682 test1683 \
+test1680 test1681 test1682 test1683 test1684 \
 \
 test1700 test1701 test1702 test1703 test1704 test1705 test1706 test1707 \
 test1708 test1709 test1710 test1711 test1712 test1713 \
diff --git a/tests/data/test1684 b/tests/data/test1684
new file mode 100644
index 0000000000..3de6c4d611
--- /dev/null
+++ b/tests/data/test1684
@@ -0,0 +1,46 @@
+<?xml version="1.0" encoding="US-ASCII"?>
+<testcase>
+<info>
+<keywords>
+FTP
+MDTM
+</keywords>
+</info>
+
+<reply>
+<data>
+a joke
+</data>
+<mdtm>
+213 2003040a102659
+</mdtm>
+</reply>
+
+# Client-side
+<client>
+<server>
+ftp
+</server>
+<name>
+FTP with malformed MDTM response
+</name>
+<command>
+ftp://%HOSTIP:%FTPPORT/%TESTNUMBER -z "apr 1 2025 08:00:00"
+</command>
+</client>
+
+# Verify data after the test has been "shot"
+<verify>
+<protocol crlf="yes">
+USER anonymous
+PASS ftp@example.com
+PWD
+MDTM %TESTNUMBER
+EPSV
+TYPE I
+SIZE %TESTNUMBER
+RETR %TESTNUMBER
+QUIT
+</protocol>
+</verify>
+</testcase>