Vulnerability · Published Jul 15, 2021 · Assigned by GitHub_M

CVE-2021-32764YouTube Onebox susceptible to XSS

High 8.1

In plain English

A high-severity cross-site scripting in discourse from discourse. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 46% of all known vulnerabilities).

Severity (CVSS 3.1)8.1High

Exploit odds (30 days)0.5%top 54.1% of all CVEs

Exploited in the wildNo reportsnot in CISA KEV

Attack toolingNoneno public tooling known

Official description

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 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.

Affected products (as reported)

Vendor	Product	Versions
discourse	discourse	<= 2.7.5

Weakness: CWE-79 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

References

https://github.com/discourse/discourse/security/advisories/GHSA-9x4c-29xg-56hw x_refsource_CONFIRM