// For flags

CVE-2020-24659

gnutls: Heap buffer overflow in handshake with no_renegotiation alert sent

Severity Score

7.5
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

1
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

An issue was discovered in GnuTLS before 3.6.15. A server can trigger a NULL pointer dereference in a TLS 1.3 client if a no_renegotiation alert is sent with unexpected timing, and then an invalid second handshake occurs. The crash happens in the application's error handling path, where the gnutls_deinit function is called after detecting a handshake failure.

Se detectó un problema en GnuTLS versiones anteriores a 3.6.15. Un servidor puede desencadenar una desreferencia del puntero NULL en un cliente TLS versión 1.3, si una alerta no_renegotiation es enviada con una sincronización no prevista y luego se produce un segundo protocolo de enlace no válido. El bloqueo ocurre en la ruta de manejo de errores de la aplicación, donde la función gnutls_deinit es llamada después de detectar un fallo en el protocolo de enlace

A flaw was found in GnuTLS, where the server can trigger the client to run into heap buffer overflow if a no_renegotiation alert is sent in an unexpected timing. This flaw allows the client to crash at the session deinitialization timing. The highest threat from this vulnerability is to system availability.

*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
Partial
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2020-08-26 CVE Reserved
  • 2020-09-04 CVE Published
  • 2024-08-04 CVE Updated
  • 2024-08-04 First Exploit
  • 2024-08-11 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
CWE
  • CWE-20: Improper Input Validation
  • CWE-476: NULL Pointer Dereference
  • CWE-787: Out-of-bounds Write
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Gnu
Search vendor "Gnu"
Gnutls
Search vendor "Gnu" for product "Gnutls"
< 3.6.15
Search vendor "Gnu" for product "Gnutls" and version " < 3.6.15"
-
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
Opensuse
Search vendor "Opensuse"
Leap
Search vendor "Opensuse" for product "Leap"
15.1
Search vendor "Opensuse" for product "Leap" and version "15.1"
-
Affected
Opensuse
Search vendor "Opensuse"
Leap
Search vendor "Opensuse" for product "Leap"
15.2
Search vendor "Opensuse" for product "Leap" and version "15.2"
-
Affected
Canonical
Search vendor "Canonical"
Ubuntu Linux
Search vendor "Canonical" for product "Ubuntu Linux"
20.04
Search vendor "Canonical" for product "Ubuntu Linux" and version "20.04"
lts
Affected