CVE-2020-20341Public exploitNetwork attack vector

Internal network probing via unrestricted image retrieval

Published Sep 1, 2021 · Updated Aug 4, 2024

SSRF in YzmCMS 5.5 allows remote authenticated users to probe internal hosts and ports through crafted article image URLs. The grab_image() function extracts image sources from article content and passes HTTP-containing URLs to readfile() without restricting destination hosts or ports. Access to article creation or editing and enabling the save-remote-files-locally option are required; the server then requests the supplied internal URL and stores the response as an image.

CVSS severity7.5
High
EPSS probability1.32%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

SSRF in YzmCMS 5.5 allows remote authenticated users to probe internal hosts and ports through crafted article image URLs. The grab_image() function extracts image sources from article content and passes HTTP-containing URLs to readfile() without restricting destination hosts or ports. Access to article creation or editing and enabling the save-remote-files-locally option are required; the server then requests the supplied internal URL and stores the response as an image.

The record

CVE
CVE-2020-20341
Published
Sep 1, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-918, T1046
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 1, 2021CVE 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 privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.5INCIBE-CERTCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
5.0INCIBE-CERTAV:N/AC:L/Au:N/C:P/I:N/A:N

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

Weakness, pattern, technique

CWE-918Server-Side Request Forgery (SSRF)
T1046Network Service Discovery

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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