CVE-2025-0520Public exploitNetwork attack vector

Unauthenticated code execution via ineffective extension allowlist

Published Apr 29, 2025 · Updated Jun 23, 2026

Unrestricted file upload in ShowDoc before 2.8.7 allows remote attackers to execute arbitrary PHP through the image-upload endpoint. PageController's uploadImg action neither checks login state nor applies its intended extension allowlist because it assigns allowExts instead of Think\Upload's exts property. An unauthenticated request with an obfuscated .php filename writes a web-accessible script, granting code execution under the web server account.

CVSS severity9.4
Critical
EPSS probability2.61%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Unrestricted file upload in ShowDoc before 2.8.7 allows remote attackers to execute arbitrary PHP through the image-upload endpoint. PageController's uploadImg action neither checks login state nor applies its intended extension allowlist because it assigns allowExts instead of Think\Upload's exts property. An unauthenticated request with an obfuscated .php filename writes a web-accessible script, granting code execution under the web server account.

The record

CVE
CVE-2025-0520
Published
Apr 29, 2025
Updated
Jun 23, 2026
Vendor
ShowDoc
Product
ShowDoc
Classifications
CWE-434, CAPEC-1, T1190, T1505.003
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 29, 2025CVE publishedPublication date reported by the CVE source.
  2. Jun 23, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <2.8.7

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

ShowDoc · ShowDocversion=0 <2.8.7

Published CVSS scores

9.4VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:L/SC:H/SI:H/SA:L

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-434Unrestricted Upload of File with Dangerous Type
CAPEC-1Accessing Functionality Not Properly Constrained by ACLs
T1190Exploit Public-Facing Application
T1505.003Web Shell

Public exploit references

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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