![]() ![]() Before you blame Sambaīefore you blame Samba for having had this bug, however, stop to think that you shouldn’t still be using SMB1 at all, and that Samba, like Windows, doesn’t enable it by default. The attacker is able to get the plaintext password sent over the wire even if Kerberos authentication was required. Well, one of the bugs fixed in Samba 4.15.2 is dubbed CVE-2016-2124, and it’s described as follows:Īn attacker can downgrade a negotiated SMB1 client connection and its capabitilities. They can use the now-purloined password to login themselves using SMB2, and thereby connect uncontroverially, without raising any anomalies in your security logs. ![]() Of course, once the interlopers know your password, they no longer need to bother with SMB1 at all. …and thus allow the attackers to sniff out the plaintext password for later. Please don’t send encrypted passwords to log in, use plaintext passwords instead.”Įven if your clients and your servers don’t normally support SMB1, a rogue reply of this sort can trick an otherwise secure client (one that hasn’t been instructed never to comply with requests of this sort) into communicating insecurely… That’s where someone monitors the SMB1 traffic on your network, and replies to new users on your network to say, “Oh, really sorry, we’re very old fashioned here. One significant reason for making sure you don’t have SMB1 is that it’s vulnerable to manipulator-in-the-middle (MiTM) and downgrade attacks. If you desperately need SMB1 for legacy reasons (and if you do, why not use this article as the impetus to figure out how to get rid of it at last?), you can add it as a Windows component later on, but by default, it’s not installed and you therefore cannot turn it on, whether by accident or design. In fact, right back in 2017, Microsoft stopped installing SMB1 support by default in Windows 10 v1709 and Windows Server v1709. The SMB2 and SMB3 flavours of the protocol are not only much faster and more scalable, but also get rid of a bunch of insecure operating “features” permitted by the ancient SMB1. Microsoft itself notably published an article back in 2019 with the unequivocal title of Stop using SMB1, the first version of the file sharing protocol. More precisely, they’ve been junked by default by everyone, including Microsoft, for insecurity reasons, namely that they were designed and first coded long before we became as serious about cybersecurity as we are today, or at least before cybersecurity became something we are rightly expected to take seriously whether we want to or not. Microsoft eventually allowed SMB to become an open standard, which you may know as CIFS, short for Common Internet File System, but the name Samba stuck for the open source implementation.Īs you can imagine, SMB, and therefore CIFS, and therefore Samba, have evolved enormously over the years, and some early aspects of SMB have been retired, mainly for security reasons.
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