RCE in Cmsimple
CVE-2021-47735
CMSimple 5.4 contains an authenticated remote code execution vulnerability that allows logged-in attackers to inject malicious PHP code into template files. Attackers can exploit the template editing functionality by crafting a reverse shell payload and saving it through the template editing endpoint with a valid CSRF token.
Vulnerability class: RCE (Remote Code Execution)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.009 (57.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 58th percentile — 57.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.009 · newest: 0.009 · change: +0.000
Affected products
- Cmsimple — versions 5.4
Weakness classification (CWE)
References
- www.exploit-db.com/exploits/50356 (Exploit, exploit)
- www.cmsimple.org/ (Product, product)
- www.vulncheck.com/advisories/cmsimple-authenticated-remote-code-execution-via-t… (Third Party Advisory, third-party-advisory)
Frequently asked questions
- What is CVE-2021-47735?
- CVE-2021-47735 is a high-severity vulnerability in Cmsimple, classified under Code Injection. CVSS score: 8.8/10. Published 2025-12-23.
- How severe is CVE-2021-47735?
- High severity. CVSS v3 base score is 8.8 out of 10.