Cyber Resilience

CVE-2024-35227

High

Published: 03 July 2024

Published
03 July 2024
Modified
26 August 2025
KEV Added
Patch
CVSS Score v3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0017 38.7th percentile
Risk Priority 15 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2024-35227 is a high-severity Improper Input Validation (CWE-20) vulnerability in Discourse Discourse. Its CVSS base score is 7.5 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Application or System Exploitation (T1499.004); ranked at the 38.7th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

Discourse is an open-source discussion platform. Prior to version 3.2.3 on the `stable` branch and version 3.3.0.beta3 on the `tests-passed` branch, Oneboxing against a carefully crafted malicious URL can reduce the availability of a Discourse instance. The problem has been…

more

patched in version 3.2.3 on the `stable` branch and version 3.3.0.beta3 on the `tests-passed` branch. There are no known workarounds available for this vulnerability.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1499.004 Application or System Exploitation Impact
Adversaries may exploit software vulnerabilities that can cause an application or system to crash and deny availability to users.
Why these techniques?

CVE-2024-35227 enables remote, unauthenticated denial of service via a crafted URL in Discourse's Onebox feature, causing application resource exhaustion or disruption, directly facilitating T1499.004 (Endpoint Denial of Service: Application or System Exploitation).

Affected Assets

discourse
discourse
≤ 3.2.2

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-20

Security testing and developer training directly verify and enforce proper input validation, reducing exploitability of injection and malformed-data weaknesses.

addresses: CWE-20

Security testing and evaluation at multiple SDLC stages directly detects missing or flawed input validation, with the required remediation process ensuring fixes are applied.

addresses: CWE-20

Directly implements checks on information inputs to reject invalid data before processing.

addresses: CWE-20

Spam protection mechanisms perform filtering and detection on inbound/outbound messages, directly compensating for missing or weak input validation of unsolicited content.

References