// For flags

CVE-2021-3738

Gentoo Linux Security Advisory 202309-06

Severity Score

8.8
*CVSS v3.1

Exploit Likelihood

< 1%
*EPSS

Affected Versions

3
*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

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.

En DCE/RPC es posible compartir los manejadores (cookies para el estado de los recursos) entre múltiples conexiones por medio de un mecanismo llamado "association groups". Estos manejadores pueden hacer referencia a conexiones a nuestra base de datos sam.ldb. Sin embargo, mientras la base de datos era compartida correctamente, el estado de las credenciales del usuario sólo era apuntado, y cuando una conexión dentro de ese grupo de asociación terminaba, la base de datos quedaba apuntando a una "struct session_info" no válida. El resultado más probable en este caso es un bloqueo, pero es posible que un uso de memoria previamente liberada permita apuntar a un estado de usuario diferente y esto podría permitir un acceso más privilegiado

Stefan Metzmacher discovered that Samba incorrectly handled SMB1 client connections. A remote attacker could possibly use this issue to downgrade connections to plaintext authentication. Andrew Bartlett discovered that Samba incorrectly mapping domain users to local users. An authenticated attacker could possibly use this issue to become root on domain members. Andrew Bartlett discovered that Samba did not correctly sandbox Kerberos tickets issues by an RODC. An RODC could print administrator tickets, contrary to expectations. Various other issues were also addressed.

*Credits: N/A
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Attack Vector
Network
Attack Complexity
Low
Authentication
Single
Confidentiality
Partial
Integrity
Partial
Availability
Partial
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2021-08-26 CVE Reserved
  • 2021-11-11 CVE Published
  • 2024-08-03 CVE Updated
  • 2025-03-30 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-416: Use After Free
CAPEC
Affected Vendors, Products, and Versions (3)