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Spring Boot Welcome Page Denial of Service

High severity GitHub Reviewed Published May 26, 2023 to the GitHub Advisory Database • Updated Nov 7, 2023

Package

maven org.springframework.boot:spring-boot-autoconfigure (Maven)

Affected versions

>= 3.0.0, < 3.0.7
>= 2.7.0, < 2.7.12
>= 2.6.0, < 2.6.15
< 2.5.15

Patched versions

3.0.7
2.7.12
2.6.15
2.5.15

Description

In Spring Boot versions 3.0.0 - 3.0.6, 2.7.0 - 2.7.11, 2.6.0 - 2.6.14, 2.5.0 - 2.5.14 and older unsupported versions, there is potential for a denial-of-service (DoS) attack if Spring MVC is used together with a reverse proxy cache.

Specifically, an application is vulnerable if all of the conditions are true:

  • The application has Spring MVC auto-configuration enabled. This is the case by default if Spring MVC is on the classpath.
  • The application makes use of Spring Boot's welcome page support, either static or templated.
  • Your application is deployed behind a proxy which caches 404 responses.

Your application is NOT vulnerable if any of the following are true:

  • Spring MVC auto-configuration is disabled. This is true if WebMvcAutoConfiguration is explicitly excluded, if Spring MVC is not on the classpath, or if spring.main.web-application-type is set to a value other than SERVLET.
  • The application does not use Spring Boot's welcome page support.
  • You do not have a proxy which caches 404 responses.

Affected Spring Products and Versions

Spring Boot

3.0.0 to 3.0.6 2.7.0 to 2.7.11 2.6.0 to 2.6.14 2.5.0 to 2.5.14

Older, unsupported versions are also affected
Mitigation

Users of affected versions should apply the following mitigations:

  • 3.0.x users should upgrade to 3.0.7+
  • 2.7.x users should upgrade to 2.7.12+
  • 2.6.x users should upgrade to 2.6.15+
  • 2.5.x users should upgrade to 2.5.15+

Users of older, unsupported versions should upgrade to 3.0.7+ or 2.7.12+.

Workarounds: configure the reverse proxy not to cache 404 responses and/or not to cache responses to requests to the root (/) of the application.

References

Published by the National Vulnerability Database May 26, 2023
Published to the GitHub Advisory Database May 26, 2023
Reviewed May 26, 2023
Last updated Nov 7, 2023

Severity

High

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS score

0.124%
(48th percentile)

Weaknesses

CVE ID

CVE-2023-20883

GHSA ID

GHSA-xf96-w227-r7c4

Source code

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