CVE-2021-45904Public exploitNetwork attack vector

Stored XSS via port-forward name rendering

Published Dec 27, 2021 · Updated Aug 4, 2024

Stored cross-site scripting in OpenWrt 21.02.1 allows remote authenticated users to run script in an administrator's browser via a port-forward name. Public records identify the Port Forwards Add Name screen as the input and rendering locus but do not disclose the exact handler or escaping failure. Exploitation requires low-privileged network access and a victim to view the affected interface; the published impact is limited to browser-context data access or modification.

CVSS severity5.4
Medium
EPSS probability0.52%
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 OpenWrt 21.02.1 allows remote authenticated users to run script in an administrator's browser via a port-forward name. Public records identify the Port Forwards Add Name screen as the input and rendering locus but do not disclose the exact handler or escaping failure. Exploitation requires low-privileged network access and a victim to view the affected interface; the published impact is limited to browser-context data access or modification.

The record

CVE
CVE-2021-45904
Published
Dec 27, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 27, 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

Compare your product and version with the public record. A matching version still requires validation against your environment.

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

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

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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1059.007Command and Scripting Interpreter: JavaScript/JScript

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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