// For flags

CVE-2022-43945

kernel: nfsd buffer overflow by RPC message over TCP with garbage data

Severity Score

7.5
*CVSS v3.1

Exploit Likelihood

< 1%
*EPSS

Affected Versions

8
*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

The Linux kernel NFSD implementation prior to versions 5.19.17 and 6.0.2 are vulnerable to buffer overflow. NFSD tracks the number of pages held by each NFSD thread by combining the receive and send buffers of a remote procedure call (RPC) into a single array of pages. A client can force the send buffer to shrink by sending an RPC message over TCP with garbage data added at the end of the message. The RPC message with garbage data is still correctly formed according to the specification and is passed forward to handlers. Vulnerable code in NFSD is not expecting the oversized request and writes beyond the allocated buffer space. CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

La implementación NFSD del kernel de Linux anterior a las versiones 5.19.17 y 6.0.2 es vulnerable al desbordamiento del búfer. NFSD rastrea el número de páginas retenidas por cada subproceso NFSD combinando los búferes de recepción y envío de una llamada a procedimiento remoto (RPC) en una única matriz de páginas. Un cliente puede forzar la reducción del búfer de envío enviando un mensaje RPC a través de TCP con datos basura agregados al final del mensaje. El mensaje RPC con datos basura todavía está formado correctamente según la especificación y se pasa a los controladores. El código vulnerable en NFSD no espera la solicitud de gran tamaño y escribe más allá del espacio de búfer asignado. CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

A buffer overflow flaw was found in the Linux kernel nfsd (network file system) subsystem. The way a user sends RPC over TCP with excess data added at the end of the message could allow a remote user to starve the resources, causing a denial of service.

Kyle Zeng discovered that the sysctl implementation in the Linux kernel contained a stack-based buffer overflow. A local attacker could use this to cause a denial of service (system crash) or execute arbitrary code. Tamás Koczka discovered that the Bluetooth L2CAP handshake implementation in the Linux kernel contained multiple use-after-free vulnerabilities. A physically proximate attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. It was discovered that the NFSD implementation in the Linux kernel did not properly handle some RPC messages, leading to a buffer overflow. A remote attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code.

*Credits: N/A
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High
Attack Vector
Network
Attack Complexity
Low
Authentication
None
Confidentiality
None
Integrity
None
Availability
Complete
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2022-10-26 CVE Reserved
  • 2022-11-04 CVE Published
  • 2024-08-03 CVE Updated
  • 2025-03-18 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-131: Incorrect Calculation of Buffer Size
  • CWE-770: Allocation of Resources Without Limits or Throttling
CAPEC
Affected Vendors, Products, and Versions (8)