CVE-2023-45556 — Cross Site Scripting vulnerability in Mybb Mybb Forums v

Cross Site Scripting vulnerability in Mybb Mybb Forums v.1.8.33 allows a local attacker to execute arbitrary code via the theme Name parameter in the theme management component.

01What is this vulnerability?

Cross Site Scripting vulnerability in Mybb Mybb Forums v.1.8.33 allows a local attacker to execute arbitrary code via the theme Name parameter in the theme management component.

02Affected products

Vendor	Product	Versions
n	a / n/a	n/a

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2023-11-06T00:00:00.000Z
• Last modified: 2024-09-05T14:16:56.909Z

09References

• github.com — https://github.com/Or4ngm4n/Mybb/blob/main/MyBB%201.8.33%20Cross%20Site%20Script…
• raw.githubusercontent.com — https://raw.githubusercontent.com/Or4ngm4n/Mybb/main/Screenshot%202023-10-08%200…
• github.com — https://github.com/mybb/mybb/security/advisories/GHSA-4xqm-3cm2-5xgf