Support Board < 3.3.5 - Agent+ Stored Cross-Site Scripting

published 2021-11-08 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-11719

cvss: 5.4; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 1.4%; EPSS 1.4% chance of exploitation in 30 days, percentile 72%
public exploits: 0; none known

The Support Board WordPress plugin before 3.3.5 allows Authenticated (Agent+) users to perform Cross-Site Scripting attacks by placing a payload in the notes field, when an administrator or any authenticated user go to the chat the XSS will be automatically executed.

Patch / fix

fixed in 1

schiocco support_board 3.3.5

Exploit prediction

1.42% chance of exploitation in the next 30 days, higher than 72% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

wpscan.com https://wpscan.com/vulnerability/19d101aa-4b60-4db4-a33b-86c826b288b0 referenced PoC, tagged "exploit" by a source, unverified
github.com https://github.com/itsjeffersonli/CVE-2021-24807 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
NVD	3.1	5.4	CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
NVD	2.0	3.5	AV:N/AC:M/Au:S/C:N/I:P/A:N

Affected products

Unknown Support Board

Classification

Weakness

CWE-79 Improper Neutralization of Input During Web Page Generation

Technology feeds

WordPress rss critical rss

References

wpscan.com /vulnerability/19d101aa-4b60-4db4-a33b-86c826b288b0
exploit, third-party-advisory
github.com /itsjeffersonli/CVE-2021-24807
exploit, third-party-advisory
medium.com /%40lijohnjefferson/cve-2021-24807-6bc22af2a444

Sources

CVE List CVE-2021-24807
NVD CVE-2021-24807

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary