CVE-2020-5203Network attack vector

Remote code execution via evaluated Clear key

Published Mar 11, 2020 · Updated Aug 4, 2024

Code injection in Fat-Free Framework 3.7.1 allows remote attackers to execute arbitrary code through an application that passes request data to Clear. The Clear method compiles an attacker-controlled hive key into an unset expression and evaluates it without first removing injected PHP syntax. Exploitation requires application code to pass user-controlled request, query, or form data as the Clear key, after which injected code runs in the application's PHP process.

CVSS severity9.8
Critical
EPSS probability2.14%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Code injection in Fat-Free Framework 3.7.1 allows remote attackers to execute arbitrary code through an application that passes request data to Clear. The Clear method compiles an attacker-controlled hive key into an unset expression and evaluates it without first removing injected PHP syntax. Exploitation requires application code to pass user-controlled request, query, or form data as the Clear key, after which injected code runs in the application's PHP process.

The record

CVE
CVE-2020-5203
Published
Mar 11, 2020
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-74, CWE-94, CWE-20, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 11, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.8GitHub Advisory DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.5NIST NVDAV:N/AC:L/Au:N/C:P/I:P/A:P

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-74Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
CWE-94Improper Control of Generation of Code ('Code Injection')
CWE-20Improper Input Validation
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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