HOMEVULNERABILITIESCVE-2020-5203
CRITICAL

CVE-2020-5203

CWE-20Published: March 11, 2020· Updated: Jun 17, 2026

9.8
CVSS v3.1

Official Description

In Fat-Free Framework 3.7.1, attackers can achieve arbitrary code execution if developers choose to pass user controlled input (e.g., $_REQUEST, $_GET, or $_POST) to the framework's Clear method.

NVD Source

Technical Analysis

CVE-2020-5203 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.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected Vendors & Products

fatfreeframework1 product(s)
fat-free framework
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

PATCHhttps://github.com/bcosca/fatfree-core/commit/dae95a0baf3963a9ef87c17cee52f78f77e21829
PATCHhttps://github.com/bcosca/fatfree-core/commit/dae95a0baf3963a9ef87c17cee52f78f77e21829
ADVISORYhttps://github.com/bcosca/fatfree/releases
ADVISORYhttps://github.com/bcosca/fatfree/releases

All References (4)

→
https://github.com/bcosca/fatfree-core/commit/dae95a0baf3963a9ef87c17cee52f78f77e21829Patch · Third Party Advisory
→
https://github.com/bcosca/fatfree/releasesRelease Notes · Third Party Advisory
→
https://github.com/bcosca/fatfree-core/commit/dae95a0baf3963a9ef87c17cee52f78f77e21829Patch · Third Party Advisory
→
https://github.com/bcosca/fatfree/releasesRelease Notes · Third Party Advisory

Quick Facts

CVE IDCVE-2020-5203
CVSS Score9.8 / 10
SeverityCRITICAL
WeaknessCWE-20
CISA KEVNo
Affected1 vendor(s)
PublishedMar 11, 2020

Related CVEs (CWE-20)

CVE-2003-1487
10.0
CVE-2004-0840
10.0
CVE-2026-47928
10.0
CVE-2021-26622
10.0
CVE-2008-0244
10.0
CVE-2008-1157
10.0

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2020-5203 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. CVE data is provided under the NVD usage policy.
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