Check if the Data field exists

Co-Authored-By: gpotter2 <10530980+gpotter2@users.noreply.github.com>
secdev · Jun 22, 2024 · 1e857c9 · 1e857c9
1 parent ea7cdaf
commit 1e857c9
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Showing 2 changed files with 11 additions and 1 deletion.
diff --git a/scapy/layers/smb.py b/scapy/layers/smb.py
@@ -788,7 +788,7 @@ def post_build(self, pkt, pay):
         )
 
     def mysummary(self):
-        if self.DataLen:
+        if getattr(self, "Data", None) is not None:
             return self.sprintf("Tran %Name% ") + self.Data.mysummary()
         return self.sprintf("Tran %Name%")
 

diff --git a/test/scapy/layers/smb.uts b/test/scapy/layers/smb.uts
@@ -203,3 +203,13 @@ assert pkt[SMBMailslot_Write].Data.OpCode == 1
 assert pkt[SMBMailslot_Write].Data.ServerName == b"MACBOOKPRO-122A\x00"
 assert pkt[SMBMailslot_Write].Data.Comment == b"Super's MacBook Pro"
 assert pkt[SMBMailslot_Write].Data.Signature == 0xAA55
+
+= OSS-Fuzz Findings
+
+# SMBTransaction_Request
+from io import BytesIO
+# Issue 69637
+file = BytesIO(b'M<\xb2\xa1\x02\x00\x04\x00\x00\x00\x02\xff\xa1\x00\x00\x00\xff\xff\x00\x00\x01\x00\x00\x00\r\x82\xe8Y[\xc6P"\xa1\xb2\x00_h\x00\x00\x00\x00\x10\x94\x00\x01\x00\x00\x1d%\xcb(\xce\x08\x00U\xfa\xf7\x8c\x00\x00@\x00?\x11\xa7R\xe0\xa8\x01\xa1d\xb2\xc3\xd4\n_\x00\x8a \x00\x00\x01\x00\x00\x00\x01\xff\x00\x00\x00\x10\x94\x00\x01\x00\x00\x1d%\xcb(\xce\x08\x00U\xfa\xf7\x8c\x00\x00@\x00?\x11\xa7R\xe0\xa8\x01\xa1d\xb2\xc3\xd4\n_\x00\x8a\xb2\x00\xa1a\xffl\xff\xff\xef\x00\xff\x01\x00\x08\xa1\xa1E\xf9\x00\xa1\x00\x00?\x8c\x08?\x11\x00\xc3\x00+\x10M<\x1a\x01\x00\xffSMB%d\x01\x05\x00\x00\x00\x00\x00\x00\x00\xd4\xc3\xb2\xa1\x02\x00\x04\x00\x00\x00\xf7\x8c\x00\x00@\x00?\x11\xa7R\xe0\xa8\x01\xa1d\xb2\xc3\xd4\n_\x00\x8a\xb2\x00\xa1a\xffl\xff\xff\xef\x00\xff\x01\x00\x08\xa1\xa1')
+
+l = rdpcap(file)
+assert l[0][NBTDatagram].summary() == "NBTDatagram / SMB_Header / Tran b''"