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 /.
CVE-2020-27386
Score elevated to 9.0 because EPSS predicts 73% probability of exploitation within the next 30 days (top 0.6% of all CVEs). NVD baseline CVSS 8.8 retained for reference. Confidence: see factors.
- High exploitation likelihood — EPSS 73%
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 8.8
- EG Score
- 9.0(high)
- EG Risk
- 74(Track)EG Risk 74/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity90% × 45%Exploitation73% × 40%Automatability30% × 15%Action: Routine — remediate on your standard cadence. - EPSS
- 99.4%
- KEV
- Not listed
Published
November 12, 2020
Last Modified
November 21, 2024
References (8)
- cve@mitrehttp://packetstormsecurity.com/files/160411/FlexDotnetCMS-1.5.8-Arbitrary-ASP-File-Upload.html
- cve@mitrehttps://blog.vonahi.io/whats-in-a-re-name/
- cve@mitrehttps://github.com/MacdonaldRobinson/FlexDotnetCMS/releases/tag/v1.5.9
- cve@mitrehttps://github.com/rapid7/metasploit-framework/pull/14339
- af854a3a-2127-422b-91ae-364da2661108http://packetstormsecurity.com/files/160411/FlexDotnetCMS-1.5.8-Arbitrary-ASP-File-Upload.html
- af854a3a-2127-422b-91ae-364da2661108https://blog.vonahi.io/whats-in-a-re-name/
- af854a3a-2127-422b-91ae-364da2661108https://github.com/MacdonaldRobinson/FlexDotnetCMS/releases/tag/v1.5.9
- af854a3a-2127-422b-91ae-364da2661108https://github.com/rapid7/metasploit-framework/pull/14339
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 7× in last 7d / 28× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-07-23 01:52 UTCEG score recompute▲ 0.20
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- 2026-06-24 14:03 UTCEPSS rescore
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- 2026-06-07 12:45 UTCOSV refresh
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- 2026-05-29 13:42 UTCEPSS rescore
- 2026-05-23 05:15 UTCEG score recompute
- 2026-05-23 05:15 UTCGHSA enrichment
Publicly available exploits
(1 reference)Working exploit code is in the public domain (1 Metasploit module). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.
- Metasploitexploit/windows/http/flexdotnetcms_upload_exec✓ verifiedFirst seen Sep 28, 2020
FlexDotnetCMS Arbitrary ASP File Upload
Open source ↗
Frequently asked(5)
What is CVE-2020-27386?
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Dependency Blast Radius
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