CVE-2020-23207Network attack vector

Stored XSS via unescaped attribute values

Published Jul 1, 2021 · Updated Aug 4, 2024

Stored cross-site scripting in phplist 3.5.3 allows remote authenticated users to execute arbitrary web scripts via crafted Edit Values input. The Configure Attributes Edit Values handler stores attacker-controlled values and reflects them without HTML-entity encoding; removing script tags does not neutralize event-handler payloads. Access requires a phplist account that can edit attribute values, and exploitation runs script in other users’ browsers when the stored value is rendered.

CVSS severity3.5
Low
EPSS probability0.54%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored cross-site scripting in phplist 3.5.3 allows remote authenticated users to execute arbitrary web scripts via crafted Edit Values input. The Configure Attributes Edit Values handler stores attacker-controlled values and reflects them without HTML-entity encoding; removing script tags does not neutralize event-handler payloads. Access requires a phplist account that can edit attribute values, and exploitation runs script in other users’ browsers when the stored value is rendered.

The record

CVE
CVE-2020-23207
Published
Jul 1, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-79
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 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

5.4NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
3.5NVDAV:N/AC:M/Au:S/C:N/I:P/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.

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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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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