[Security] Bump spring-core from 4.3.18.RELEASE to 4.3.21.RELEASE

[dependabot-preview]

Bumps spring-core from 4.3.18.RELEASE to 4.3.21.RELEASE. This update includes a security fix.

Vulnerabilities fixed

Sourced from The GitHub Security Advisory Database.

Denial of Service in Spring Framework Spring Framework, version 5.1, versions 5.0.x prior to 5.0.10, versions 4.3.x prior to 4.3.20, and older unsupported versions on the 4.2.x branch provide support for range requests when serving static resources through the ResourceHttpRequestHandler, or starting in 5.0 when an annotated controller returns an org.springframework.core.io.Resource. A malicious user (or attacker) can add a range header with a high number of ranges, or with wide ranges that overlap, or both, for a denial of service attack. This vulnerability affects applications that depend on either spring-webmvc or spring-webflux. Such applications must also have a registration for serving static resources (e.g. JS, CSS, images, and others), or have an annotated controller that returns an org.springframework.core.io.Resource. Spring Boot applications that depend on spring-boot-starter-web or spring-boot-starter-webflux are ready to serve static resources out of the box and are therefore vulnerable.

Affected versions: < 4.3.20

Commits

• ca50a47 Release version 4.3.21.RELEASE
• 9600e01 Revised alias definition example in reference documentation
• e9f7c35 ResolvableType-based matching consistently respects generic factory method re...
• cf8479c Upgrade to Tomcat 8.5.35, Netty 4.1.31, Gson 2.8.5, Jackson 2.8.11.3
• 1c1b942 DefaultResponseErrorHandler detects non-standard error code as well
• 85b5c5a Polishing
• ed9afa3 FastByteArrayOutputStream.read byte-to-int conversion
• 22f4b1c SerializedBeanFactoryReference falls back to dummy with specific id
• abacc6d BEST_MATCHING_HANDLER_ATTRIBUTE for spring-webmvc
• 8d668ac Up-to-date version and link in ASM/CGLIB/Objenesis package javadoc
• Additional commits viewable in compare view

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