CVE-2021-40105 Cross-site scripting in n/a
Attackers can inject malicious scripts via Markdown comments in Concrete CMS, potentially leading to session hijacking or code execution.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2021-40105?
CVE-2021-40105 is a medium-severity cross-site scripting vulnerability in Concretecms Concrete Cms, published on 27 Sep 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
An issue was discovered in Concrete CMS through 8.5.5. There is XSS via Markdown Comments.
Weakness: CWE-79
Which versions are affected by CVE-2021-40105?
It affects 1 product.
Products include Concretecms Concrete Cms.
How do I fix CVE-2021-40105?
No fix has been published for CVE-2021-40105 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2021-40105 being exploited?
There is no known exploitation of CVE-2021-40105 in the wild and no public exploit code.
Other vulnerabilities in Concretecms Concrete Cms
- CVE-2023-48648 Concrete CMS allows unauthorized access because directories can be created with insecure permissions
- CVE-2022-21829 Code injection in concrete CMS
- CVE-2021-22958 Server-Side Request Forgery vulnerability in concrete5
- CVE-2021-40098 Path traversal in n/a
- CVE-2026-8134 Concrete CMS Vulnerable to Relative Path Traversal
Sources
Also known as GHSA-5x56-gcx7-98rh.