Delta DIAView path traversal allows remote file read/write
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Critical path traversal in Delta DIAView industrial automation software enables unauthenticated remote file access; update to v4.3.0.
Delta Electronics DIAView version 4.2.0.0 contains a path traversal vulnerability (CVE-2025-53417, CWE-22) that allows remote attackers to read or write arbitrary files on affected systems without authentication or user interaction. The vulnerability carries a CVSS v3.1 score of 9.8 and CVSS v4.0 score of 9.3, reflecting its severity: network-accessible, low attack complexity, and high impact to confidentiality, integrity, and availability. DIAView is deployed worldwide across critical infrastructure sectors including chemical, manufacturing, energy, transportation, and water systems, making this a significant threat to operational technology environments.
No active exploitation has been reported to CISA at the time of this advisory. The researcher hir0ot, working with Trend Micro Zero Day Initiative, reported the flaw responsibly. Delta has released version 4.3.0 as the remediation; administrators should prioritize patching affected systems. In the interim, organizations should apply network segmentation, restrict Internet exposure of control systems, use VPNs for remote access, and place DIAView behind firewalls isolated from business networks. Standard OT security hygiene—blocking untrusted links and unsolicited attachments—remains essential.
Mentioned in this report
Detection guidance
Web Request with Directory Traversal Sequences in URI
Detects HTTP requests whose URI path or query contains plain or encoded ../ and ..\ sequences, the pattern used to exploit path-traversal flaws such as CVE-2025-53417 in Delta DIAView. Auto-generated starting point — validate and tune in your environment before deploying. IOC matches can false-positive on shared infrastructure and decay as adversary infrastructure rotates.
title: Web Request with Directory Traversal Sequences in URI
description: Detects HTTP requests whose URI path or query contains plain, URL-encoded
or double-encoded directory traversal sequences. This is the generic behaviour behind
path-traversal exploitation of public-facing applications such as Delta DIAView
(CVE-2025-53417). Does not rely on any product-specific endpoint.
tags:
- attack.initial-access
- attack.t1190
- attack.discovery
- attack.t1083
logsource:
category: webserver
detection:
selection_stem:
cs-uri-stem|contains:
- ../
- ..\
- ..%2f
- ..%5c
- '%2e%2e%2f'
- '%2e%2e/'
- '%2e%2e%5c'
- '%2e%2e\'
- '%252e%252e'
selection_query:
cs-uri-query|contains:
- ../
- ..\
- ..%2f
- ..%5c
- '%2e%2e%2f'
- '%2e%2e/'
- '%2e%2e%5c'
- '%2e%2e\'
- '%252e%252e'
filter_rejected:
sc-status:
- 400
- 404
condition: 1 of selection_* and not filter_rejected
falsepositives:
- Web applications that legitimately pass relative paths in query parameters (e.g.
document viewers or SPA routers)
- Authorised vulnerability scanners probing for traversal flaws
level: medium
id: 1d2c8083-a385-5d36-a303-33b62bee47af
status: experimental
author: Vorant
references:
- https://www.cisa.gov/news-events/ics-advisories/icsa-25-219-01
Directory Traversal Request Targeting Sensitive System Files
Detects HTTP requests combining traversal sequences with well-known sensitive OS or configuration file names, indicating arbitrary file read attempts against a public-facing application. Auto-generated starting point — validate and tune in your environment before deploying. IOC matches can false-positive on shared infrastructure and decay as adversary infrastructure rotates.
title: Directory Traversal Request Targeting Sensitive System Files
description: Detects web requests that combine directory traversal sequences with
sensitive file names (win.ini, boot.ini, web.config, SAM, /etc/passwd). Indicates
an attempt at arbitrary file read via path traversal, as in CVE-2025-53417 (Delta
DIAView). Generic to the technique, not tied to a product URL.
tags:
- attack.initial-access
- attack.t1190
- attack.discovery
- attack.t1083
logsource:
category: webserver
detection:
selection_traversal:
cs-uri|contains:
- ../
- ..\
- ..%2f
- ..%5c
- '%2e%2e%2f'
- '%2e%2e/'
- '%2e%2e%5c'
- '%252e%252e'
selection_target:
cs-uri|contains:
- windows/win.ini
- windows\win.ini
- windows%5cwin.ini
- windows%2fwin.ini
- boot.ini
- web.config
- system32
- config/sam
- etc/passwd
- etc%2fpasswd
condition: selection_traversal and selection_target
falsepositives:
- Authorised vulnerability scanners or penetration tests running traversal checks
level: high
id: bd1fc052-585c-564a-b37c-a176abab5f4f
status: experimental
author: Vorant
references:
- https://www.cisa.gov/news-events/ics-advisories/icsa-25-219-01
Behavioural rules are generated from public reporting — validate in your environment before deploying.
Source reporting: https://www.cisa.gov/news-events/ics-advisories/icsa-25-219-01
What this brief leaves out
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