Fix ReDoS vulnerability in multipart parser

This commit fixes a ReDoS vulnerability when parsing the Content-Disposition field in multipart attachments Thanks to @ooooooo_q for the patch! [CVE-2022-44571]
rack · Jan 17, 2023 · b79bb5a · b79bb5a
1 parent 7a9d76a
commit b79bb5a
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/lib/rack/multipart/parser.rb b/lib/rack/multipart/parser.rb
@@ -23,7 +23,7 @@ class Error < StandardError; end
     VALUE = /"(?:\\"|[^"])*"|#{TOKEN}/
     BROKEN = /^#{CONDISP}.*;\s*filename=(#{VALUE})/i
     MULTIPART_CONTENT_TYPE = /Content-Type: (.*)#{EOL}/ni
-    MULTIPART_CONTENT_DISPOSITION = /Content-Disposition:.*;\s*name=(#{VALUE})/ni
+    MULTIPART_CONTENT_DISPOSITION = /Content-Disposition:[^:]*;\s*name=(#{VALUE})/ni
     MULTIPART_CONTENT_ID = /Content-ID:\s*([^#{EOL}]*)/ni
     # Updated definitions from RFC 2231
     ATTRIBUTE_CHAR = %r{[^ \x00-\x1f\x7f)(><@,;:\\"/\[\]?='*%]}