Skip to content
Noroxi
NVD / CVE Program· CNA mitre

CVE-2020-21359: An arbitrary file upload vulnerability in the Template Upload function of Maccms10 allows attackers bypass the suffix whitelist verification…

CriticalCVSS 9.8 · v3.1—No exploit No fix recorded

Noroxi assessment

Priority: Plan (action score 40/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 1.7% (FIRST EPSS); higher than 77.9% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • According to the record, no fixed version is available yet.

Add it to your regular patch cycle. Update when a fix is released; follow the vendor's advisory.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

An arbitrary file upload vulnerability in the Template Upload function of Maccms10 allows attackers bypass the suffix whitelist verification to execute arbitrary code via adding a character to the end of the uploaded file's name.

Published
Aug 11, 2021
Updated
Jun 16, 2026
EPSS
1.7% · 77th percentile

Report tools

JSON

Action score

40

Plan

Add it to your regular patch cycle.

CVSS
39 / 40 · 9.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
1 / 30 · 1.7%

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • No fixed version yet

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2020-21359

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

One daily email digest (06:00 UTC); connect a webhook for KEV listings and weaponized exploits every 10 minutes on paid plans, on the hour on the free plan.

Your free account also gets you

  • CVE alerts: add the products and versions you run, get the new CVEs that affect them
  • Uptime monitoring: 1 site, instant email when it goes down
  • Add your domain: subdomains and takeover risk scanned every week (1 domain)
  • 10 scans an hour on the security tools, at most 30 a day (3 a day without an account), an API key and MCP
  • All your scans in one panel: findings, what changed in the last scan, a report per domain or per client (PDF, share link)
All free tools

Sign up with email · Have an account? Sign in

Free account, no card. Unfollow any time.

Don't want an account? Get "Exploited this week" by email every MondayDon't want an account? RSS feed for maccms records
Is your version affected? Check it

Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

We use this product, ask for help

Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
maccmsmaccms

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • maccms maccms10.0

Same product

maccms: all records

Other highest-scoring records for the same primary product.

  • CVE-2017-17733Maccms 8.x allows remote command execution via the wd parameter in an index.php?m=vod-search request.
    52Plan
  • CVE-2021-45786In maccms v10, an attacker can log in through /index.php/user/login in the "col" and "openid" parameters to gain privileges.
    39Monitor
  • CVE-2025-28091maccms10 v2025.1000.4047 has a Server-Side Request Forgery (SSRF) vulnerability via Add Article.
    36Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2019-9829Mar 14, 2019 · Maccms 10 allows remote attackers to execute arbitrary PHP code by entering this code in a template/default_pc/html/art Edit action.
    36Monitor
  • ← EarlierCVE-2018-19465Jun 7, 2019 · Maccms through 8.0 allows XSS via the site_keywords field to index.php?m=system-config because of tpl/module/system.php and…
    24Monitor
  • Later →CVE-2020-21362Aug 11, 2021 · A cross site scripting (XSS) vulnerability in the background search function of Maccms10 allows attackers to execute arbitrary web scripts…
    21Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

No fix version is recorded for this entry. Check the references for vendor advisories.

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

Not on record for this CVE: EPSS history · patch commit or PR link · researcher credit · variant or chain candidate · public bounty program.

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-434 · Unrestricted Upload of File with Dangerous Type

CVSS vector

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

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

All records