// For flags

CVE-2023-50247

h2o QUIC state exhaustion DoS

Severity Score

7.5
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

h2o is an HTTP server with support for HTTP/1.x, HTTP/2 and HTTP/3. The QUIC stack (quicly), as used by H2O up to commit 43f86e5 (in version 2.3.0-beta and prior), is susceptible to a state exhaustion attack. When H2O is serving HTTP/3, a remote attacker can exploit this vulnerability to progressively increase the memory retained by the QUIC stack. This can eventually cause H2O to abort due to memory exhaustion. The vulnerability has been resolved in commit d67e81d03be12a9d53dc8271af6530f40164cd35. HTTP/1 and HTTP/2 are not affected by this vulnerability as they do not use QUIC. Administrators looking to mitigate this issue without upgrading can disable HTTP/3 support.

h2o es un servidor HTTP compatible con HTTP/1.x, HTTP/2 y HTTP/3. La pila QUIC (rápidamente), tal como la utiliza H2O hasta el commit 43f86e5 (en la versión 2.3.0-beta y anteriores), es susceptible a un ataque de agotamiento de estado. Cuando H2O sirve HTTP/3, un atacante remoto puede aprovechar esta vulnerabilidad para aumentar progresivamente la memoria retenida por la pila QUIC. Esto eventualmente puede causar que H2O cancele debido al agotamiento de la memoria. La vulnerabilidad se resolvió en el commit d67e81d03be12a9d53dc8271af6530f40164cd35. HTTP/1 y HTTP/2 no se ven afectados por esta vulnerabilidad ya que no utilizan QUIC. Los administradores que quieran mitigar este problema sin realizar una actualización pueden desactivar la compatibilidad con HTTP/3.

*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
High
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
Low
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2023-12-05 CVE Reserved
  • 2023-12-12 CVE Published
  • 2023-12-20 EPSS Updated
  • 2024-08-02 CVE Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-770: Allocation of Resources Without Limits or Throttling
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Dena
Search vendor "Dena"
 H2o
Search vendor "Dena" for product "H2o"
 <= 2.2.6
Search vendor "Dena" for product "H2o" and version " <= 2.2.6"
-
Affected
Dena
Search vendor "Dena"
 H2o
Search vendor "Dena" for product "H2o"
 2.3.0
Search vendor "Dena" for product "H2o" and version "2.3.0"
beta1
Affected
Dena
Search vendor "Dena"
 H2o
Search vendor "Dena" for product "H2o"
 2.3.0
Search vendor "Dena" for product "H2o" and version "2.3.0"
beta2
Affected