CVE-2024-38821
Published: 28 October 2024
Summary
CVE-2024-38821 is a critical-severity Allocation of Resources Without Limits or Throttling (CWE-770) vulnerability in Spring WebFlux (inferred from references). Its CVSS base score is 9.1 (Critical).
Operationally, ranked in the top 5.7% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
Deeper analysis
CVE-2024-38821 affects Spring WebFlux applications that use Spring's static resources support together with Spring Security authorization rules. The flaw permits bypass of non-permitAll authorization constraints applied to those resources when all three conditions are met: the application must be built on WebFlux, must rely on Spring's static-resource handling, and must enforce a restrictive authorization rule on the static paths.
An unauthenticated remote attacker can exploit the issue over the network to access protected static content, resulting in high-impact disclosure or modification of sensitive files while leaving availability unaffected. The CVSS 9.1 rating reflects the absence of required credentials or user interaction and the complete compromise of confidentiality and integrity.
The Spring advisory at spring.io/security/cve-2024-38821 and the related NetApp notice describe the conditions required for exposure and direct users to updated Spring Security and Spring Framework releases that correct the authorization enforcement for static resources.
EPSS remains flat at 0.1309 with no material increase after disclosure.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2024-3011
Vulnerability details
Spring WebFlux applications that have Spring Security authorization rules on static resources can be bypassed under certain circumstances. For this to impact an application, all of the following must be true: * It must be a WebFlux application * It…
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must be using Spring's static resources support * It must have a non-permitAll authorization rule applied to the static resources support
- CWE(s)
Related Threats
No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.
Affected Assets
Mitigating Controls
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
This control implements explicit throttling on session allocation, addressing the weakness of allocating resources without limits.
Plan testing exercises resource allocation limits and throttling during simulated failures, directly addressing weaknesses that allow unbounded resource use.
Contingency plan updates ensure recovery strategies address unbounded resource allocation, making it harder for attackers to exploit lack of throttling to cause prolonged outages.
Provides continuity when unbounded resource allocation at the primary site leads to exhaustion and downtime.
Alternate services allow operations to continue when primary allocation of resources lacks limits or throttling.
Explicit planning of security-related actions requires defining limits, windows, and resource allocations, making allocation without throttling far less likely.
Measures of performance include tracking allocation behavior and throttling effectiveness, reducing the window for resource exhaustion attacks.
Imposes an inactivity-based limit on network resource allocation, throttling the number of concurrently held connections.