All samba versions 4.9.x before 4.9.18, 4.10.x before 4.10.12 and 4.11.x before 4.11.5 have an issue where if it is set with "log level = 3" (or above) then the string obtained from the client, after a failed character conversion, is printed. Such strings can be provided during the NTLMSSP authentication exchange. In the Samba AD DC in particular, this may cause a long-lived process(such as the RPC server) to terminate. (In the file server case, the most likely target, smbd, operates as process-per-client and so a crash there is harmless).
Last updated 25 August 2025
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.
Last updated 18 August 2025
All Samba versions 4.x.x before 4.9.17, 4.10.x before 4.10.11 and 4.11.x before 4.11.3 have an issue, where the S4U (MS-SFU) Kerberos delegation model includes a feature allowing for a subset of clients to be opted out of constrained delegation in any way, either S4U2Self or regular Kerberos authentication, by forcing all tickets for these clients to be non-forwardable. In AD this is implemented by a user attribute delegationnotallowed (aka not-delegated), which translates to disallow-forwardable. However the Samba AD DC does not do that for S4U2Self and does set the forwardable flag even if the impersonated client has the not-delegated flag set.
All Samba versions 4.x.x before 4.9.17, 4.10.x before 4.10.11 and 4.11.x before 4.11.3 have an issue, where the (poorly named) dnsserver RPC pipe provides administrative facilities to modify DNS records and zones. Samba, when acting as an AD DC, stores DNS records in LDAP. In AD, the default permissions on the DNS partition allow creation of new records by authenticated users. This is used for example to allow machines to self-register in DNS. If a DNS record was created that case-insensitively matched the name of the zone, the ldbqsort() and dnsnamecompare() routines could be confused into reading memory prior to the list of DNS entries when responding to DnssrvEnumRecords() or DnssrvEnumRecords2() and so following invalid memory as a pointer.
Last updated 25 August 2025
Last updated 25 August 2025
A flaw was found in samba versions 4.9.x up to 4.9.13, samba 4.10.x up to 4.10.8 and samba 4.11.x up to 4.11.0rc3, when certain parameters were set in the samba configuration file. An unauthenticated attacker could use this flaw to escape the shared directory and access the contents of directories outside the share.