CVE-2021-23192

Related Vulnerabilities: CVE-2021-23192  

A flaw was found in the way samba implemented DCE/RPC. If a client to a Samba server sent a very large DCE/RPC request, and chose to fragment it, an attacker could replace later fragments with their own data, bypassing the signature requirements.

Description

A flaw was found in the way samba implemented DCE/RPC. If a client to a Samba server sent a very large DCE/RPC request, and chose to fragment it, an attacker could replace later fragments with their own data, bypassing the signature requirements.

Mitigation

Setting

dcesrv:max auth states=0
 in the smb.conf will provide some mitigation against this issue.

Additional Information

  • Bugzilla 2019666: CVE-2021-23192 samba: Subsequent DCE/RPC fragment injection vulnerability
  • FAQ: Frequently asked questions about CVE-2021-23192