Cyber Resilience

CVE-2024-28121

HighPublic PoC

Published: 12 March 2024

Published
12 March 2024
Modified
03 December 2025
KEV Added
Patch
CVSS Score v3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0146 81.2th percentile
Risk Priority 18 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2024-28121 is a high-severity Unsafe Reflection (CWE-470) vulnerability in Stimulusreflex Stimulusrelfex. Its CVSS base score is 8.8 (High).

Operationally, ranked in the top 18.8% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability details

stimulus_reflex is a system to extend the capabilities of both Rails and Stimulus by intercepting user interactions and passing them to Rails over real-time websockets. In affected versions more methods than expected can be called on reflex instances. Being able…

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to call some of them has security implications. To invoke a reflex a websocket message of the following shape is sent: `\"target\":\"[class_name]#[method_name]\",\"args\":[]`. The server will proceed to instantiate `reflex` using the provided `class_name` as long as it extends `StimulusReflex::Reflex`. It then attempts to call `method_name` on the instance with the provided arguments. This is problematic as `reflex.method method_name` can be more methods that those explicitly specified by the developer in their reflex class. A good example is the instance_variable_set method. This vulnerability has been patched in versions 3.4.2 and 3.5.0.rc4. Users unable to upgrade should: see the backing GHSA advisory for mitigation advice.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

stimulusreflex
stimulusrelfex
3.5.0 · ≤ 3.4.2

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.

addresses: CWE-470

Externally controlled class or code selection can be resolved and invoked inside the chamber, surfacing unsafe reflection without system impact.

References