CyberRota Analysis
AI-GeneratedThe vulnerability affects the Linux kernel's ksmbd component, where an authenticated attacker can exploit the NTLM authentication process to prematurely destroy a victim's session by manipulating the NTLM blob username field. This flaw allows the attacker to disrupt legitimate user sessions, potentially leading to denial of service for affected users. Organizations using Linux systems with ksmbd should prioritize patching this vulnerability to safeguard against session hijacking and unauthorized disruptions.
Original NVD Description
In the Linux kernel, the following vulnerability has been resolved: ksmbd: defer destroy_previous_session() until after NTLM authentication In ntlm_authenticate(), destroy_previous_session() is called using a user pointer resolved from the client-supplied NTLM blob username field before the NTLMv2 response is validated. An authenticated attacker can set the NTLM blob username to match a victim account and set PreviousSessionId to the victim's session ID; destroy_previous_session() destroys the victim's session while ksmbd_decode_ntlmssp_auth_blob() subsequently rejects the request with -EPERM. Move destroy_previous_session() and the prev_id assignment to after ksmbd_decode_ntlmssp_auth_blob() returns success and use sess->user rather than the pre-authentication lookup result. This matches the ordering already used by krb5_authenticate(), where destroy_previous_session() is called only after ksmbd_krb5_authenticate() returns success.