Fix CRLF Injection in AsyncWebHeader.cpp

mathieucarbou · mathieucarbou · commit 632c221125e2 · 2025-06-27T21:17:32.000+02:00
diff --git a/src/AsyncWebHeader.cpp b/src/AsyncWebHeader.cpp
@@ -11,6 +11,11 @@ AsyncWebHeader::AsyncWebHeader(const String &data) {
   if (index < 0) {
     return;
   }
+  if (data.indexOf('\r') >= 0 || data.indexOf('\n') >= 0) {
+    // Note: do not log as info, warn or error because this could flood the logs without being able to filter this out
+    log_v("Invalid character in HTTP header");
+    return;  // Invalid header format
+  }
   _name = data.substring(0, index);
   _value = data.substring(index + 2);
 }

Original file line number	Diff line number	Diff line change
`@@ -11,6 +11,11 @@ AsyncWebHeader::AsyncWebHeader(const String &data) {`
`11`	`11`	`if (index < 0) {`
`12`	`12`	`return;`
`13`	`13`	`}`
	`14`	`+ if (data.indexOf('\r') >= 0 \|\| data.indexOf('\n') >= 0) {`
	`15`	`+ // Note: do not log as info, warn or error because this could flood the logs without being able to filter this out`
	`16`	`+ log_v("Invalid character in HTTP header");`
	`17`	`+ return; // Invalid header format`
	`18`	`+ }`
`14`	`19`	`_name = data.substring(0, index);`
`15`	`20`	`_value = data.substring(index + 2);`
`16`	`21`	`}`