Samba

The Samba AD DC includes checks when adding service principals names (SPNs) to an account to ensure that SPNs do not alias with those already in the database. Some of these checks are able to be bypassed if an account modification re-adds an SPN that was previously present on that account, such as one added when a computer is joined to a domain. An attacker who has the ability to write to an account can exploit this to perform a denial-of-service attack by adding an SPN that matches an existing service. Additionally, an attacker who can intercept traffic can impersonate existing services, resulting in a loss of confidentiality and integrity.Show less

A flaw was found in the Samba AD LDAP server. The AD DC database audit logging module can access LDAP message values freed by a preceding database module, resulting in a use-after-free issue. This issue is only possible when modifying certain privileged attributes, such as userAccountControl.Show less

A flaw was found in Samba. The KDC accepts kpasswd requests encrypted with any key known to it. By encrypting forged kpasswd requests with its own key, a user can change other users' passwords, enabling full domain takeover.Show less

A flaw was found in Samba. Some SMB1 write requests were not correctly range-checked to ensure the client had sent enough data to fulfill the write, allowing server memory contents to be written into the file (or printer) instead of client-supplied data. The client cannot control the area of the server memory written to the file (or printer).Show less

A flaw was found in Samba. The security vulnerability occurs when KDC and the kpasswd service share a single account and set of keys, allowing them to decrypt each other's tickets. A user who has been requested to change their password, can exploit this flaw to obtain and use tickets to other services.Show less

An issue was discovered in rsync before 3.2.5 that allows malicious remote servers to write arbitrary files inside the directories of connecting peers. The server chooses which files/directories are sent to the client. However, the rsync client performs insufficient validation of file names. A malicious rsync server (or Man-in-The-Middle attacker) can overwrite arbitrary files in the rsync client target directory and subdirectories (for example, overwrite the .ssh/authorized_keys file).Show less

In DCE/RPC it is possible to share the handles (cookies for resource state) between multiple connections via a mechanism called 'association groups'. These handles can reference connections to our sam.ldb database. However while the database was correctly shared, the user credentials state was only pointed at, and when one connection within that association group ended, the database would be left pointing at an invalid 'struct session_info'. The most likely outcome here is a crash, but it is possible that the use-after-free could instead allow different user state to be pointed at and this might allow more privileged access.Show less

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.Show less

All versions of Samba prior to 4.15.5 are vulnerable to a malicious client using a server symlink to determine if a file or directory exists in an area of the server file system not exported under the share definition. SMB1 with unix extensions has to be enabled in order for this attack to succeed.Show less