An elevation of privilege vulnerability exists when an attacker establishes a vulnerable Netlogon secure channel connection to a domain controller, using the Netlogon Remote Protocol (MS-NRPC). An attacker who successfully exploited the vulnerability could run a specially crafted application on a device on the network.
To exploit the vulnerability, an unauthenticated attacker would be required to use MS-NRPC to connect to a domain controller to obtain domain administrator access.
Microsoft is addressing the vulnerability in a phased two-part rollout. These updates address the vulnerability by modifying how Netlogon handles the usage of Netlogon secure channels.
For guidelines on how to manage the changes required for this vulnerability and more information on the phased rollout, see How to manage the changes in Netlogon secure channel connections associated with CVE-2020-1472 (updated September 28, 2020).
When the second phase of Windows updates become available in Q1 2021, customers will be notified via a revision to this security vulnerability. If you wish to be notified when these updates are released, we recommend that you register for the security notifications mailer to be alerted of content changes to this advisory. See Microsoft Technical Security Notifications.
A flaw was found in the samba client, all samba versions before samba 4.11.2, 4.10.10 and 4.9.15, where a malicious server can supply a pathname to the client with separators. This could allow the client to access files and folders outside of the SMB network pathnames. An attacker could use this vulnerability to create files outside of the current working directory using the privileges of the client user.
A flaw was found in the way an LDAP search expression could crash the shared LDAP server process of a samba AD DC in samba before version 4.10. An authenticated user, having read permissions on the LDAP server, could use this flaw to cause denial of service.
A heap-buffer overflow was found in the way samba clients processed extra long filename in a directory listing. A malicious samba server could use this flaw to cause arbitrary code execution on a samba client. Samba versions before 4.6.16, 4.7.9 and 4.8.4 are vulnerable.
A flaw was found in the way samba client before samba 4.4.16, samba 4.5.14 and samba 4.6.8 used encryption with the max protocol set as SMB3. The connection could lose the requirement for signing and encrypting to any DFS redirects, allowing an attacker to read or alter the contents of the connection via a man-in-the-middle attack.
An information leak flaw was found in the way SMB1 protocol was implemented by Samba before 4.4.16, 4.5.x before 4.5.14, and 4.6.x before 4.6.8. A malicious client could use this flaw to dump server memory contents to a file on the samba share or to a shared printer, though the exact area of server memory cannot be controlled by the attacker.
Samba before versions 4.6.1, 4.5.7 and 4.4.11 are vulnerable to a malicious client using a symlink race to allow access to areas of the server file system not exported under the share definition.
smbd in Samba before 4.4.10 and 4.5.x before 4.5.6 has a denial of service vulnerability (fd_open_atomic infinite loop with high CPU usage and memory consumption) due to wrongly handling dangling symlinks.
The SMB2 implementation in Samba 3.6.x before 3.6.6, as used on the IBM Storwize V7000 Unified 1.3 before 1.3.2.3 and 1.4 before 1.4.0.1 and possibly other products, does not properly enforce CIFS share attributes, which allows remote authenticated users to (1) write to a read-only share; (2) trigger data-integrity problems related to the oplock, locking, coherency, or leases attribute; or (3) have an unspecified impact by leveraging incorrect handling of the browseable or "hide unreadable" parameter.
The RPC code generator in Samba 3.x before 3.4.16, 3.5.x before 3.5.14, and 3.6.x before 3.6.4 does not implement validation of an array length in a manner consistent with validation of array memory allocation, which allows remote attackers to execute arbitrary code via a crafted RPC call.