MEDIUM
CVE-2020-20691
CWE-434Published: September 27, 2021· Updated: Jun 17, 2026
6.5
CVSS v3.1
Official Description
An issue in Monstra CMS v3.0.4 allows attackers to execute arbitrary web scripts or HTML via bypassing the file extension filter and uploading crafted HTML files.
Technical Analysis
CVE-2020-20691 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.
The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.
CVSS v3.1 Vector Breakdown
Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityLow
IntegrityLow
AvailabilityNone
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
Affected Vendors & Products
monstra1 product(s)
monstra cms
Source: NVD CPE · 1 total CPE entries
Exploit & PoC Resources
NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.
Official Patches & Advisories
All References (2)
→
https://github.com/monstra-cms/monstra/issues/461Exploit · Issue Tracking · Third Party Advisory
→
https://github.com/monstra-cms/monstra/issues/461Exploit · Issue Tracking · Third Party Advisory
Quick Facts
CVE IDCVE-2020-20691
CVSS Score6.5 / 10
SeverityMEDIUM
WeaknessCWE-434
CISA KEVNo
Affected1 vendor(s)
PublishedSep 27, 2021
Related CVEs (CWE-434)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2020-20691 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.