// For flags

CVE-2024-2511

Unbounded memory growth with session handling in TLSv1.3

Severity Score

3.7
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

Track
*SSVC
Descriptions

Issue summary: Some non-default TLS server configurations can cause unbounded
memory growth when processing TLSv1.3 sessions

Impact summary: An attacker may exploit certain server configurations to trigger
unbounded memory growth that would lead to a Denial of Service

This problem can occur in TLSv1.3 if the non-default SSL_OP_NO_TICKET option is
being used (but not if early_data support is also configured and the default
anti-replay protection is in use). In this case, under certain conditions, the
session cache can get into an incorrect state and it will fail to flush properly
as it fills. The session cache will continue to grow in an unbounded manner. A
malicious client could deliberately create the scenario for this failure to
force a Denial of Service. It may also happen by accident in normal operation.

This issue only affects TLS servers supporting TLSv1.3. It does not affect TLS
clients.

The FIPS modules in 3.2, 3.1 and 3.0 are not affected by this issue. OpenSSL
1.0.2 is also not affected by this issue.

Resumen del problema: algunas configuraciones de servidor TLS no predeterminadas pueden causar un crecimiento ilimitado de la memoria al procesar sesiones TLSv1.3. Resumen de impacto: un atacante puede explotar ciertas configuraciones del servidor para desencadenar un crecimiento ilimitado de la memoria que conduciría a una denegación de servicio. Este problema puede ocurrir en TLSv1.3 si se utiliza la opción SSL_OP_NO_TICKET no predeterminada (pero no si también se configura la compatibilidad con early_data y se utiliza la protección antirrepetición predeterminada). En este caso, bajo ciertas condiciones, el caché de la sesión puede entrar en un estado incorrecto y no se vaciará correctamente a medida que se llena. La caché de la sesión seguirá creciendo de forma ilimitada. Un cliente malintencionado podría crear deliberadamente el escenario para que este fallo fuerce una denegación de servicio. También puede ocurrir por accidente durante el funcionamiento normal. Este problema solo afecta a los servidores TLS que admiten TLSv1.3. No afecta a los clientes TLS. Los módulos FIPS en 3.2, 3.1 y 3.0 no se ven afectados por este problema. OpenSSL 1.0.2 tampoco se ve afectado por este problema.

A flaw was found in OpenSSL. A malicious client can trigger an uncontrolled memory consumption, resulting in a Denial of Service. This issue occurs due to OpenSSL's TLSv3.1 session cache going into an incorrect state, leading to it failing to flush properly as it fills. OpenSSL must be configured with the non-default SSL_OP_NO_TICKET option enabled to be vulnerable. This issue only affects TLSv1.3 servers, while TLS clients are not affected.

*Credits: Manish Patidar (Hewlett Packard Enterprise), Matt Caswell
CVSS Scores
Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
Low
* Common Vulnerability Scoring System
SSVC
  • Decision:Track
Exploitation
None
Automatable
No
Tech. Impact
Partial
* Organization's Worst-case Scenario
Timeline
  • 2024-03-15 CVE Reserved
  • 2024-04-08 CVE Published
  • 2024-10-14 CVE Updated
  • 2024-10-15 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-400: Uncontrolled Resource Consumption
  • CWE-1325: Improperly Controlled Sequential Memory Allocation
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
OpenSSL
Search vendor "OpenSSL"
OpenSSL
Search vendor "OpenSSL" for product "OpenSSL"
>= 3.2.0 < 3.2.2
Search vendor "OpenSSL" for product "OpenSSL" and version " >= 3.2.0 < 3.2.2"
en
Affected
OpenSSL
Search vendor "OpenSSL"
OpenSSL
Search vendor "OpenSSL" for product "OpenSSL"
>= 3.1.0 < 3.1.6
Search vendor "OpenSSL" for product "OpenSSL" and version " >= 3.1.0 < 3.1.6"
en
Affected
OpenSSL
Search vendor "OpenSSL"
OpenSSL
Search vendor "OpenSSL" for product "OpenSSL"
>= 3.0.0 < 3.0.14
Search vendor "OpenSSL" for product "OpenSSL" and version " >= 3.0.0 < 3.0.14"
en
Affected