CVE-2017-12151

Se ha encontrado un fallo en la forma en la que el cliente samba en versiones anteriores a samba 4.4.16, samba 4.5.14 y samba 4.6.8 utilizaba cifrado con el protocolo max establecido en SMB3. La conexión podía perder el requisito de firmar y cifrar con cualquier redirección DFS, lo que permitía a un atacante leer o alterar el contenido de la conexión mediante un ataque Man-in-the-Middle (MitM).

A flaw was found in the way samba client used encryption with the max protocol set as SMB3. The connection could lose the requirement for signing and encrypting to any DFS redirects, allowing an attacker to read or alter the contents of the connection via a man-in-the-middle attack.

Stefan Metzmacher discovered that Samba incorrectly enforced SMB signing in certain situations. A remote attacker could use this issue to perform a man in the middle attack. Stefan Metzmacher discovered that Samba incorrectly handled encryption across DFS redirects. A remote attacker could use this issue to perform a man in the middle attack. Yihan Lian and Zhibin Hu discovered that Samba incorrectly handled memory when SMB1 is being used. A remote attacker could possibly use this issue to obtain server memory contents. Various other issues were also addressed.