// For flags

CVE-2018-12232

kernel: NULL pointer dereference if close and fchownat system calls share a socket file descriptor

Severity Score

5.9
*CVSS v3

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

In net/socket.c in the Linux kernel through 4.17.1, there is a race condition between fchownat and close in cases where they target the same socket file descriptor, related to the sock_close and sockfs_setattr functions. fchownat does not increment the file descriptor reference count, which allows close to set the socket to NULL during fchownat's execution, leading to a NULL pointer dereference and system crash.

En net/socket.c en el kernel de Linux hasta la versión 4.17.1, hay una condición de carrera entre fchownat y close en los casos en los que apuntan al mismo descriptor de archivo socket. Esto está relacionado con las funciones sock_close y sockfs_setattr. fchownat no incrementa el conteo de referencia del descriptor de archivos, lo que permite que close establezca el socket como NULL durante la ejecución de fchownat lo que conduce a una desreferencia de puntero NULL y a un cierre inesperado del sistema.

A NULL pointer dereference issue was found in the Linux kernel. If the close() and fchownat() system calls share a socket file descriptor as an argument, then the two calls can race and trigger a NULL pointer dereference leading to a system crash and a denial of service.

*Credits: N/A
CVSS Scores
Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High
Attack Vector
Network
Attack Complexity
Medium
Authentication
None
Confidentiality
None
Integrity
None
Availability
Complete
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2018-06-12 CVE Reserved
  • 2018-06-12 CVE Published
  • 2024-08-05 CVE Updated
  • 2024-12-17 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
  • CWE-476: NULL Pointer Dereference
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Linux
Search vendor "Linux"
 Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
 <= 4.17.1
Search vendor "Linux" for product "Linux Kernel" and version " <= 4.17.1"
-
Affected