CVE-2020-9309
HIGHEPSS 76th pctlDescription
Silverstripe CMS through 4.5 can be susceptible to script execution from malicious upload contents under allowed file extensions (for example HTML code in a TXT file). When these files are stored as protected or draft files, the MIME detection can cause browsers to execute the file contents. Uploads stored as protected or draft files are allowed by default for authorised users only, but can also be enabled through custom logic as well as modules such as silverstripe/userforms. Sites using the previously optional silverstripe/mimevalidator module can configure MIME whitelists rather than extension whitelists, and hence prevent this issue. Sites on the Common Web Platform (CWP) use this module by default, and are not affected.
How to fix
Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.
CVSS v3 Vector
Exploitability
Impact
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Exploit Intelligence
Elevated risk: more likely to be exploited than 76% of all known CVEs.
References
Related Vulnerabilities
Other CWE-434 (Unrestricted File Upload) vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2017-12617 | High | 8.1 | 100% | KEV | Fix |
| CVE-2018-15961 | Critical | 9.8 | 100% | KEV | - |
| CVE-2021-31207 | Medium | 6.6 | 100% | KEV + Ransom | Fix |
| CVE-2017-12615 | High | 8.1 | 100% | KEV + Ransom | - |
| CVE-2025-31324 | Critical | 10.0 | 99% | KEV + Ransom | - |
| CVE-2024-50623 | Critical | 9.8 | 99% | KEV + Ransom | Fix |
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Start freeThis product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2024-11-21.