CVE-2020-27386

Name: CVE-2020-27386
Creator: NVD / NIST
Published: 2020-11-12T19:15:15.207+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 8.8/10EPSS 72.87%

Last modified Jun 17, 2026

CVE-2020-27386 is a high-severity vulnerability rated 8.8/10 on the CVSS scale. 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>.. EPSS estimates a 72.87% chance of exploitation in the next 30 days.

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>.

Metrics

CVSS 3.1

8.8/10

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

72.87%

99.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-434

Affected Software

Vendor	Product	Versions
Flexdotnetcms Project	Flexdotnetcms	< 1.5.9

References

http://packetstormsecurity.com/files/160411/FlexDotnetCMS-1.5.8-Arbitrary-ASP-File-Upload.htmlThird Party Advisory, VDB Entry
https://blog.vonahi.io/whats-in-a-re-name/Exploit, Third Party Advisory
https://github.com/MacdonaldRobinson/FlexDotnetCMS/releases/tag/v1.5.9Release Notes, Third Party Advisory
https://github.com/rapid7/metasploit-framework/pull/14339Exploit, Patch, Third Party Advisory
http://packetstormsecurity.com/files/160411/FlexDotnetCMS-1.5.8-Arbitrary-ASP-File-Upload.htmlThird Party Advisory, VDB Entry
https://blog.vonahi.io/whats-in-a-re-name/Exploit, Third Party Advisory
https://github.com/MacdonaldRobinson/FlexDotnetCMS/releases/tag/v1.5.9Release Notes, Third Party Advisory
https://github.com/rapid7/metasploit-framework/pull/14339Exploit, Patch, Third Party Advisory

Timeline

Published: Nov 12, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-27386?

How severe is CVE-2020-27386?

CVE-2020-27386 has a CVSS score of 8.8/10 (HIGH severity). The EPSS model estimates a 72.87% probability of exploitation in the next 30 days.

How do I fix CVE-2020-27386?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2020-27386?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST