CVE-2020-27386

CVE-2020-27386 is a high-severity vulnerability in Flexdotnetcms Project Flexdotnetcms with a CVSS 3.x base score of 8.8. Its EPSS exploit-prediction score of 73% places it in the 99th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-434.

Key facts

Description

An unrestricted file upload issue in FlexDotnetCMS before v1.5.9 allows an authenticated remote attacker to upload and execute arbitrary files by using the FileManager to upload malicious code (e.g., ASP code) in the form of a safe file type (e.g., a TXT file), and then using the FileEditor (in v1.5.8 and prior) or the FileManager's rename function (in v1.5.7 and prior) to rename the file to an executable extension (e.g., ASP), and finally executing the file via an HTTP GET request to /<path_to_file>.

Frequently asked questions

What is CVE-2020-27386?
An unrestricted file upload issue in FlexDotnetCMS before v1.5.9 allows an authenticated remote attacker to upload and execute arbitrary files by using the FileManager to upload malicious code (e.g., ASP code) in the form of a safe file type (e.g., a TXT file), and then using the FileEditor (in v1.5.8 and prior) or the FileManager's rename function (in v1.5.7 and prior) to rename the file to an executable extension (e.g., ASP), and finally executing the file via an HTTP GET request to /<path_to_file>.
How severe is CVE-2020-27386?
CVE-2020-27386 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2020-27386 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 73% (99th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-27386?
CVE-2020-27386 affects Flexdotnetcms Project Flexdotnetcms. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-27386?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2020-27386 published?
CVE-2020-27386 was published on 2020-11-12 and last updated on 2026-06-17.

References

Affected products (1)

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