This causes an HTML textarea that is filled with unescaped input to break and execute a simple JavaScript.

blns.base64.json

@@ -394,6 +394,7 @@
      "PGlmcmFtZSBzcmM9aHR0cDovL2hhLmNrZXJzLm9yZy9zY3JpcHRsZXQuaHRtbCA8Cg==",
      "IjthbGVydCgnWFNTJyk7Ly8K",
      "PHBsYWludGV4dD4K",
+     "PC90ZXh0YXJlYT48c2NyaXB0PmFsZXJ0KDEyMyk8L3NjcmlwdD4=",
      "MTtEUk9QIFRBQkxFIHVzZXJzCg==",
      "MSc7IERST1AgVEFCTEUgdXNlcnMtLSAxCg==",
      "JyBPUiAxPTEgLS0gMQo=",

blns.base64.txt

@@ -495,6 +495,7 @@ PGlmcmFtZSBzcmM9aHR0cDovL2hhLmNrZXJzLm9yZy9zY3JpcHRsZXQuaHRtbCA8Cg==
 IjthbGVydCgnWFNTJyk7Ly8K
 PHBsYWludGV4dD4K
 aHR0cDovL2EvJSUzMCUzMAo=
+PC90ZXh0YXJlYT48c2NyaXB0PmFsZXJ0KDEyMyk8L3NjcmlwdD4=
 
 # SQL Injection
 #

blns.json

@@ -415,6 +415,7 @@
   "<i onwheel=alert(1)> Scroll over me </i>", 
   "<plaintext>", 
   "http://a/%%30%30", 
+  "</textarea><script>alert(123)</script>",
   "1;DROP TABLE users", 
   "1'; DROP TABLE users-- 1", 
   "' OR 1=1 -- 1", 

blns.txt

@@ -506,6 +506,7 @@ perl -e 'print "<IMG SRC=java\0script:alert(\"XSS\")>";' > out
 <i onwheel=alert(1)> Scroll over me </i>
 <plaintext>
 http://a/%%30%30
+</textarea><script>alert(123)</script>
 
 #	SQL Injection
 #