// For flags

CVE-2020-29129

QEMU: slirp: out-of-bounds access while processing ARP/NCSI packets

Severity Score

4.3
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

ncsi.c in libslirp through 4.3.1 has a buffer over-read because it tries to read a certain amount of header data even if that exceeds the total packet length.

El archivo ncsi.c en libslirp versiones hasta 4.3.1, presenta una sobrescritura del búfer porque intenta leer una determinada cantidad de datos del encabezado inclusive si excede la longitud total del paquete

An out-of-bounds access issue was found in the SLiRP user networking implementation of QEMU. It could occur while processing ARP/NCSI packets, if the packet length was shorter than required to accommodate respective protocol headers and payload. A privileged guest user may use this flaw to potentially leak host information bytes.

Qiuhao Li discovered that libslirp incorrectly handled certain header data lengths. An attacker inside a guest could possibly use this issue to leak sensitive information from the host. This issue only affected Ubuntu 20.04 LTS and Ubuntu 20.10. It was discovered that libslirp incorrectly handled certain udp packets. An attacker inside a guest could possibly use this issue to leak sensitive information from the host. 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
Low
Integrity
None
Availability
None
Attack Vector
Local
Attack Complexity
High
Privileges Required
High
User Interaction
None
Scope
Changed
Confidentiality
Low
Integrity
None
Availability
None
Attack Vector
Network
Attack Complexity
Low
Authentication
Single
Confidentiality
Partial
Integrity
None
Availability
None
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2020-11-26 CVE Reserved
  • 2020-11-26 CVE Published
  • 2024-08-04 CVE Updated
  • 2025-03-30 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-125: Out-of-bounds Read
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Libslirp Project
Search vendor "Libslirp Project"
 Libslirp
Search vendor "Libslirp Project" for product "Libslirp"
 <= 4.3.1
Search vendor "Libslirp Project" for product "Libslirp" and version " <= 4.3.1"
-
Affected
Fedoraproject
Search vendor "Fedoraproject"
 Fedora
Search vendor "Fedoraproject" for product "Fedora"
 32
Search vendor "Fedoraproject" for product "Fedora" and version "32"
-
Affected
Fedoraproject
Search vendor "Fedoraproject"
 Fedora
Search vendor "Fedoraproject" for product "Fedora"
 33
Search vendor "Fedoraproject" for product "Fedora" and version "33"
-
Affected
Debian
Search vendor "Debian"
 Debian Linux
Search vendor "Debian" for product "Debian Linux"
 10.0
Search vendor "Debian" for product "Debian Linux" and version "10.0"
-
Affected