CVE-2021-31156Public exploitNetwork attack vector

Unauthenticated file disclosure via raw traversal paths

Published Mar 28, 2024 · Updated Apr 8, 2025

Path traversal in Allied Telesis AT-S115 before 1.00.024 with Boot Loader 1.00.006 allows remote attackers to read device files. The web interface fails to sanitize dot-dot-slash segments in a raw URL path before serving files, allowing traversal to /etc/passwd. No authentication or user interaction is required; exposure is limited to files readable through the affected web service.

CVSS severity7.5
High
EPSS probability0.95%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Path traversal in Allied Telesis AT-S115 before 1.00.024 with Boot Loader 1.00.006 allows remote attackers to read device files. The web interface fails to sanitize dot-dot-slash segments in a raw URL path before serving files, allowing traversal to /etc/passwd. No authentication or user interaction is required; exposure is limited to files readable through the affected web service.

The record

CVE
CVE-2021-31156
Published
Mar 28, 2024
Updated
Apr 8, 2025
Vendor
Allied Telesis
Product
AT-S115
Classifications
CWE-22, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 28, 2024CVE publishedPublication date reported by the CVE source.
  2. Apr 8, 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 <1.00.024_with_boot_loader_1.00.006

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Allied Telesis · AT-S115version=0 <1.00.024_with_boot_loader_1.00.006

Published CVSS scores

7.5CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/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.

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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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
T1190Exploit Public-Facing Application

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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