CVE-2020-21654Network attack vector

Authenticated shell access via crafted ZIP upload

Published Oct 6, 2021 · Updated Aug 4, 2024

emlog v6.0 contains an arbitrary file upload vulnerability in admin/template.php that allows remote authenticated users to obtain a shell via crafted ZIP files. The component accepts a crafted ZIP during template administration, but authoritative records do not disclose the specific file-handling operation that permits shell access. Administrative authentication is required, and successful exploitation gives the attacker server-side shell capability with resulting confidentiality, integrity, and availability impact.

CVSS severity7.2
High
EPSS probability1.10%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

emlog v6.0 contains an arbitrary file upload vulnerability in admin/template.php that allows remote authenticated users to obtain a shell via crafted ZIP files. The component accepts a crafted ZIP during template administration, but authoritative records do not disclose the specific file-handling operation that permits shell access. Administrative authentication is required, and successful exploitation gives the attacker server-side shell capability with resulting confidentiality, integrity, and availability impact.

The record

CVE
CVE-2020-21654
Published
Oct 6, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
T1505.003
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Oct 6, 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 privilegesadmin

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

6.5NVDAV:N/AC:L/Au:S/C:P/I:P/A:P
7.2NVDCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1505.003Web Shell

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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