CVE-2021-4459Network attack vector

Authenticated file disclosure via relative path traversal

Published Aug 27, 2025 · Updated Aug 27, 2025

Relative path traversal in SMA Sunny Boy firmware before 3.10.27.R allows remote authenticated users to read files outside the web root. Public advisories do not identify the affected request handler or path parameter, but state that it fails to confine authorized file access to the intended web root. Valid device credentials and network access to the inverter are required, and the reported consequence is disclosure of sensitive system information.

CVSS severity6.5
Medium
EPSS probability0.67%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Relative path traversal in SMA Sunny Boy firmware before 3.10.27.R allows remote authenticated users to read files outside the web root. Public advisories do not identify the affected request handler or path parameter, but state that it fails to confine authorized file access to the intended web root. Valid device credentials and network access to the inverter are required, and the reported consequence is disclosure of sensitive system information.

The record

CVE
CVE-2021-4459
Published
Aug 27, 2025
Updated
Aug 27, 2025
Vendor
SMA Solar Technology AG
Product
Sunny Boy
Classifications
CWE-23, T1005
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 27, 2025CVE publishedPublication date reported by the CVE source.
  2. Aug 27, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0.0.0 <3.10.27.R

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

SMA Solar Technology AG · Sunny Boyversion=0.0.0 <3.10.27.R

Published CVSS scores

6.5CERT@VDECVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/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 exploitUnconfirmed

Weakness, pattern, technique

CWE-23Relative Path Traversal
T1005Data from Local System

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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