CVE-2021-27375Network attack vector

Cross-origin dashboard embedding via missing frame restriction

Published Feb 18, 2021 · Updated Aug 3, 2024

Cross-site framing in Traefik before 2.4.5 allows remote attackers to embed dashboard pages inside cross-origin IFRAME elements. The dashboard response handler omits a same-origin frame restriction, so browsers permit an unrelated origin to embed the interface. The dashboard must be network-accessible to the attacker's browser; published evidence limits the result to cross-origin framing and does not establish code execution or data disclosure.

CVSS severity5.3
Medium
EPSS probability0.77%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cross-site framing in Traefik before 2.4.5 allows remote attackers to embed dashboard pages inside cross-origin IFRAME elements. The dashboard response handler omits a same-origin frame restriction, so browsers permit an unrelated origin to embed the interface. The dashboard must be network-accessible to the attacker's browser; published evidence limits the result to cross-origin framing and does not establish code execution or data disclosure.

The record

CVE
CVE-2021-27375
Published
Feb 18, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-1021
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 18, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 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 privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.3NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
5.0NVDAV:N/AC:L/Au:N/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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-1021Improper Restriction of Rendered UI Layers or Frames

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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