Cyber Resilience

CVE-2021-32764

High

Published: 15 July 2021

Published
15 July 2021
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 8.1 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
EPSS Score 0.0024 47.0th percentile
Risk Priority 16 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-32764 is a high-severity Cross-site Scripting (CWE-79) vulnerability in Discourse Discourse. Its CVSS base score is 8.1 (High).

Operationally, ranked at the 47.0th 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. In Discourse versions 2.7.5 and prior, parsing and rendering of YouTube Oneboxes can be susceptible to XSS attacks. This vulnerability only affects sites which have modified or disabled Discourse's default Content Security Policy. The…

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issue is patched in `stable` version 2.7.6, `beta` version 2.8.0.beta3, and `tests-passed` version 2.8.0.beta3. As a workaround, ensure that the Content Security Policy is enabled, and has not been modified in a way which would make it more vulnerable to XSS attacks.

CWE(s)

Related Threats

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

Affected Assets

discourse
discourse
2.8.0 · ≤ 2.7.5

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-79

Penetration testing submits XSS payloads to web applications, detecting cross-site scripting flaws for subsequent remediation.

addresses: CWE-79

Validates web inputs to reject script-related content that could produce XSS.

addresses: CWE-79

Output validation against expected content can reject or sanitize script content in generated web pages, reducing XSS exploitability.

References