A security issue has been found in Samba versions 3.0.0 to 4.15.1. A man in the middle attack can force the client side SMB1 code to fall-back to plaintext or NTLM based authentication even if Kerberos authentication was requested by the user or application.
A security issue has been found in Samba versions 3.0.0 to 4.15.1. A man in the middle attack can force the client side SMB1 code to fall-back to plaintext or NTLM based authentication even if Kerberos authentication was requested by the user or application.
https://www.samba.org/samba/security/CVE-2016-2124.html https://www.samba.org/samba/ftp/patches/security/samba-4.15.1-security-2021-11-09.patch
Workaround ========== To mitigate the issue, ensure the following [global] smb.conf parameters are set to their default values as shown below: client lanman auth = no client NTLMv2 auth = yes client plaintext auth = no client min protocol = SMB2_02 Or use the '-k' command line option only without the -U option, which will make use of an existing krb5 ccache.