CVE-2007-2446

Múltiples desbordamientos de búfer en la región heap de la memoria en el análisis NDR en smbd en Samba versión 3.0.0 hasta 3.0.25rc3 permiten que los atacantes remotos ejecuten código arbitrario por medio de peticiones MS-RPC creadas que involucran (1) DFSEnum (netdfs_io_dfs_EnumInfo_d), (2) RFNPCNEX (smb_io_notify_option_type_data), (3) LsarAddPrivilegesToAccount (lsa_io_privilege_set), (4) NetSetFileSecurity (sec_io_acl), o (5) LsarLookupSids/LsarLookupSids2 (lsa_io_trans_name).

This vulnerability allows attackers to execute arbitrary code on vulnerable installations of Samba. User interaction is not required to exploit this vulnerability.
The specific flaw exists in the parsing of RPC requests to the LSA RPC interface. When parsing a request to LsarLookupSids/LsarLookupSids2, heap allocation is calculated based on user input. By specifying invalid values, heap blocks can be overwritten leading to remote code execution.

Several issues have been identified in Samba, the SMB/CIFS file and print server implementation for GNU/Linux. When translating SIDs to/from names using Samba local list of user and group accounts, a logic error in the smbd daemon's internal security stack may result in a transition to the root user id rather than the non-root user. The user is then able to temporarily issue SMB/CIFS protocol operations as the root user. This window of opportunity may allow the attacker to establish addition means of gaining root access to the server. Various bugs in Samba's NDR parsing can allow a user to send specially crafted MS-RPC requests that will overwrite the heap space with user defined data. Unescaped user input parameters are passed as arguments to /bin/sh allowing for remote command execution