Microsoft · Windows Smb · CVE-2025-33073
**Name of the Vulnerable Software and Affected Versions**
Microsoft Windows (affected versions not specified)
**Description**
Improper access control in the Windows SMB client, specifically within the `mrxsmb.sys` driver, allows an authorized or unauthenticated remote attacker to elevate privileges to the `NT AUTHORITYSYSTEM` level. The issue stems from weaknesses in authentication relaying, including NTLM reflection and Reflective Kerberos Relay attacks. Attackers can use authentication coercion techniques, such as forcing a request to a UNC path, to intercept authentication tickets. By manipulating `CREDENTIAL TARGET INFORMATIONW` and forcing Kerberos usage over NTLM via SPNEGO, an attacker can relay a computer account ticket (`DOMAINMACHINE$`) back to the host to gain full system control. This exploitation can occur over standard RPC and SMB services and may bypass SMB signing to relay authentication across protocols such as LDAP, LDAPS, and RPC.
**Recommendations**
At the moment, there is no information about a newer version that contains a fix for this vulnerability.