CVE-2025-15577 Unauthenticated Path Traversal in Valmet DNA Web Tools

Valmet DNA Engineering Web Tools are vulnerable to an unauthenticated path-traversal flaw (CVE-2025-15577) that allows attackers to manipulate a web maintenance service URL and read arbitrary files from affected systems — a risk that is particularly acute for organizations that run Valmet DNA in industrial control and energy environments. The vulnerability affects Valmet DNA Engineering Web Tools versions C2022 and earlier, was publicly documented in mid-February 2026, and has been rated high-to-critical by multiple vulnerability trackers; CISA published guidance for defenders alongside the advisory. //cvefeed.io/vuln/detail/CVE-2025-15577)

Background / Overview​

Valmet DNA is an automation platform widely used in the energy and critical manufacturing sectors, integrating distributed control, visualization, and engineering tools for process plants. The Engineering Web Tools component exposes web-based maintenance and engineering interfaces that operators and contractors use to administer systems. Because these interfaces often sit at the intersection of operational networks and vendor support channels, vulnerabilities in them have outsized impact on industrial safety, availability, and confidentiality.
The flaw tracked as CVE-2025-15577 is classed as a Path Traversal (CWE-22: Improper Limitation of a Pathname to a Restricted Directory). Multiple vulnerability aggregators and vendor advisories confirm the affected product versions and basic exploitability: versions of Valmet DNA Engineering Web Tools up to and including C2022 are affected, and the vulnerability allows unauthenticated attackers to craft URLs that induce the product to return arbitrary files from the server’s filesystem.
CISA issued an ICS advisory on February 19, 2026 describing the vulnerability and recommended mitigations for control-system operators; that advisory emphasizes network isolation, limiting internet exposure of control devices, and preferred use of secure remote access such as VPNs (with caveats) — standard industrial cybersecurity hylso notes the critical infrastructure sectors affected (Critical Manufacturing and Energy) and reminds operators to perform careful impact analysis before implementing defensive controls.

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Why this matters: threat model and real-world impact​

Path traversal vulnerabilities in web administration and maintenance interfaces are dangerous for three reasons:

• They are often pre-authentication or require little to no privilege to exploit, which lowers the barrier for attackers.
• They enable arbitrary file disclosure, including configuration, credential, or session files that can reveal plaintext passwords, private keys, or tokens.
• In industrial contexts, leaked credentials or configuration artifacts can be leveraged for lateral movement into operational networks, escalation to engineering workstations, and ultimately disruption of control systems.

CVE-2025-15577 specifically permits an unauthenticated attacker to manipulate the web maintenance services URL to achieve arbitrary file reads; that exact behavior maps to multiple historical incidents where directory traversal and arbitrary-file-read issues in VPNs and control-plane web UIs led to credential harvesting and long-term intrusions. Comparative incidents cited in public advisories — for example, CVE-2019-11510 (Pulse Connect Secure) and other VPN/web UI path traversal bugs — illustrate the downstream consequences: credential theft, webshell installation, and persistent access. Those precedent cases provide a realistic view of what an attacker could accomplish if they successfully exploit Valmet DNA’s path-traversal flaw.
Key potential impacts for affected organizations

• Credential theft: configuration files or databases may contain plaintext or reversible credentials for operators, historians, or connected services.
• Supply-chain and vendor access abuse: many engineering tools provide remote maintenance paths; disclosure of session tokens or config files could permit attacker impersonation of trusted vendor/contractor sessions.
• Information disclosure of safety-critical settings: misconfiguration data or engineering work files could expose safety interlocks or operational setpoints.
• Enabler for follow-on attacks: file reads can reveal secrets used to access other systems (e.g., service accounts, API keys), enabling lateral movement and full compromise.

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Technical analysis: how the vulnerability works​

CWE-22: Path Traversal fundamentals​

A path traversal occurs when an application constructs filesystem paths using untrusted user input without properly sanitizing or constraining that input. Attackers insert sequences like ../ (or encoded variants) into URLs or parameters to navigate out of intended directories and access files elsewhere on disk. When that file-reading operation happens in a privileged server process, the attacker can retrieve arbitrary filesystem content.
CVE-2025-15577 is described as precisely this class of weakness: an improper limitation of a pathname to a restricted directory in the Valmet DNA Engineering Web Tools web maintenance interface. The vulnerability specifically permits manipulation of the web maintenance services URL to cause arbitrary file reads without authentication. Public CVE listings and vendor communications indicate the affected component and the version boundary (<= C2022).

Attack surface and likely exploitation vectors​

• Publicly reachable engineering interfaces: if DNA Engineering Web Tools are exposed to corporate networks or vendor-access networks that can be reached from the internet, the risk of remote exploitation increases dramatically.
• Vendor / remote maintenance tunnels: organizations that permit vendor access to engineering interfaces over firewalls or via VPNs may inadvertently broaden exposure.
• Automation / orchestration endpoints: if maintenance operations are integrated with automated deployment or remote support tooling, leaked configuration files could be used to pivot or seed further automation attacks.

Proof-of-concept characteristics (generalized patterns)

• A crafted HTTP GET or POST to the web maintenance service endpoint with traversal sequences (../, ..%2f, etc.) inserted into a filename or resource parameter.
• A successful server response that returns the contents of an arbitrary file path (for example: /etc/passwd on Unix-like hosts or configuration databases and logs on Windows hosts).
• No authentication step required prior to file retrieval.

Note: as of publication, there are no confirmed public exploitation reports targeting this specific CVE; however, the lack of observed exploitation does not imply no risk. Historical exploitah-traversal issues in ICS software show that once proof-of-concept code becomes public, opportunistic attackers rapidly scan and probe exposed devices. CISA’s advisory similarly warns organizations to minimize external exposure and apply compensating controls.

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Affected versions and vendor response​

• Affected: Valmet DNA Engineering Web Tools — versions C2022 and earlier. This version boundary is consistent across vendor advisories and CVE registries.
• CVE identifier: CVE-2025-15577; vulnerability category: Path Traversal / Arbitrary File Read.

Valmet’s public security advisories page lists DNA-related security bulletins and instructs customers to follow vendor-provided updates and contact local customer support for fixes and guidance. The vendor typically releases patched builds or mitigations through their product update channels; for this specific CVE, Valmet published an advisory noting the issue and recommending updates. Organizations that run Valmet DNA should consult their Valmet account teams for patched releases and follow the vendor’s remediation instructions.
Third-party vulnerability trackers (e.g., Tenable, CVE aggregators) have assigned high-to-critical severity scores and published the vulnerability details to help defenders identify and prioritize remediation. These trackers aggregate vendor advisories and public vulnerability data; defenders should use them as supplementary intelligence while relying on vendor guidance for patch availability and compatibility.

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Detection: how to find signs of compromise or exposure​

Because the vulnerability permits file reads via HTTP requests, defenders can focus on both proactive discovery of vulnerable instances and reactive detection of exploitation attempts.
Proactive discovery (inventory and scanning)

• Inventory all hosts running Valmet DNA components and engineering tools. Identify versions and build numbers; if remote-access components exist, mark them high priority.
• Use authenticated product inventory where possible; if inventory agents or management tools are not available, use targeted web scanning on known management endpoints to verify version strings (only from permitted scanning hosts).
• Create an allowlist of expected web endpoints and validate configuration against vendor hardening guides.

Reactive detection (log indicators and network-level telemetry)

• Review web server and proxy logs for HTTP requests containing traversal sequences (../, ..%2f, %2e%2e%2f, etc.) targeting maintenance endpoints.
• Search logs for requests to maintenance service URLs followed by file-like suffices (for example, references to files in typical OS locationguration files).
• Monitor for unexpected downloads of configuration or credential files from maintenance endpoints.
• On Windows hosts, check filesystem access logs for reads of critical files (if file auditing is enabled), and examine access to private keys or local credential stores.

Evidence from prior ICS advisories highlights the value of log review for pre-auth web requests and for unusual POST/GET parameter patterns; CISA and incident response teams have repeatedly recommended storing and analyzing "unauthenticated web requests" logs for similar vulnerabilities.

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Recommended immediate mitigations (prioritized)​

If you operate Valmet DNA Engineering Web Tools and cannot apply a vendor patch immediately, adopt the following prioritized mitigations. These steps follow CISA’s ICS guidance and standard defense-in-depth principles.

• Isolate affected systems
• Immediately remove affected devices from direct internet exposure. Ensure engineering web tools are only reachable from trusted management networks or jump hosts.
• Restrict access with network controls
• Place the web interfaces behind firewalls and access control lists that only permit known administrator IP addresses or jump-host IPs.
• Where remote access is required, use a hardened VPN or jump host with multifactor authentication and strict endpoint posture checks.
• Implement application-layer protections
• If available, configure web application firewalls (WAF) or reverse proxies to block requests containing path-traversal patterns and to deny suspicious parameter values.
• Harden logging and monitoring
• Turn on detailed web server logging for maintenance endpoints and configure alerts for traversal-like activity.
• Retain relevant logs for forensic investigation; log rotation and centralization (SIEM) will speed detection.
• Rotate credentials and secrets
• If you suspect any access or if the system was exposed publicly, rotate service accounts, operator passwords, and API keys that could be present on the system or reachable ng tool.
• Apply vendor updates
• When Valmet releases an official patch or updated build, plan and schedule application after appropriate testing in a maintenance window. Validate the patch on non-production systems first.
• Conduct an impact analysis before remediation
• For ICS systems, any change may affect operations. Follow your change management practice, and coordinate with control engineers and safety teams prior to patches or reboots. CISA explicitly reminds operators to perform impact analysis prior to deploying defensive measures.

Short-form checklist

• Minimize external exposure (internet-facing = immediate risk).
• Restrict remote access and require MFA on management channels.
• Block traversal patterns at network perimeter and WAF.
• Enable and monitor detailed logs for maintenance endpoints.
• Rotate secrets if exposure is suspected.
• Apply vendor patches as they become available; test before deploy.

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Long-term risk reduction and best practices for ICS environments​

Path traversal and arbitrary file-read findings repeatedly underline systemic weaknesses that require structural fixes:

• Network segmentation: enforce strict separation between enterprise, vendor, and operational networks. Engineering UI components should be in segmented management VLANs accessible only by jump hosts.
• Least privilege and credential hygiene: service accounts used by engineering tools should have minimal permissions and use unique, rotated credentials stored in hardened vaults.
• Secure remote maintenance: vendor maintenance should use well-controlled, audited access mechanisms; consider temporary jump-host accounts with time-limited credentials rather than persistent vendor accounts.
• Application hardening: vendors and operators should adopt input validation libraries and secure coding practices that normalize and sanitize all path inputs, and explicitly block traversal sequences at the application layer.
• Vulnerability disclosure and patching pipeline: maintain an inventory and a prioritized patching schedule; automate patch testing where possible to shorten time-to-remediation for critical issues.
• Proactive scanning and red-teaming: periodically scan management surfaces for known classes of vulnerabilities, and conduct tabletop exercises to validate incident response for ICS-specific scenarios.

These are not new prescriptions: they are the same defense-in-depth steps that CISA, NIST, and major vendors have published for years. However, implementation in OT environments requires coordination with operations and safety teams because availability and process continuity are paramount.

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What defenders should communicate internally​

• Communicate to operational stakeholders (control engineers, plant managers) the need to evaluate exposure of Valmet management interfaces and to approve any patching/maintenance windows.
• Treat discovery of any unauthorized unauthenticated web requests or unexpected file reads as high priority for incident response and forensic preservation.
• If the Valmet environment integrates with enterprise identity or Active Directory, assume the possibility of credential leakage and validate account integrity across both OT and IT domains.
• Coordinate with vendor support (Valmet) to obtain the signed patched binaries and guidance, and consider requesting configuration checks or integrity tools from the vendor if provided.

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Vendor and ecosystem responsibilities​

• Valmet must provide clear patched releases, accompanied by installation instructions that respect OT constraints (e.g., non-disruptive patching options).
• Third-party vulnerability aggregators and vulnerability management teams should ensure their CVE metadata (severity, affected builds) is accurate and synchronized with vendor advisories to avoid confusion.
• Managed service providers and vendors who offer remote maintenance servte how they authenticate to customer DNA systems and prefer ephemeral, audited sessions with strong endpoint checks.

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Caveats and uncertainties​

• As of the CISA advisory publication (February 19, 2026), there were no confirmed public exploitations of CVE-2025-15577 reported to CISA. Absence of observed exploitation is not equivalent to lack of risk; public proof-of-concept code can appear quickly and enable widespread scanning. Defenders must not rely on the “no known exploitation” status as a reason for complacency.
• Severity scores reported by vulnerability aggregators vary (CVSS v3/v4 differences). Use the vendor’s and CISA’s guidance for prioritization in the context of your operational environment while treating the flaw as high priority due to its unauthenticated nature and potential access to sensitive files.
• Some public trackers list differing CVSS vectors and scores for the CVE; this can reflect different assessment methodologies (CVSS v3 vs v4). Where possible, defenders should compute risk using asset-criticality and exposure rather than relying solely on a single numerical severity score.

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Practical incident response steps if you detect exploitation​

If you observe suspicious requests or evidence indicating a successful arbitrary file read, follow an incident response playbook tailored for OT systems:

• Containment: immediately isolate the affected web interface from external networks while preserving forensic evidence (do not power-cycle devices that would destroy volatile logs unless safety requires it).
• Preservation: collect web server logs, proxy logs, and any captured traffic related to the suspicious requests; preserve the system image or relevant artifacts if feasible.
• Identify scope: inventory files accessed, check for subsequent authentication anomalies, and search for lateral movement indicators on OT and connected IT systems.
• Credential remediation: rotate any service or administrative credentials suspected of exposure; force reboots of persistent remote sessions that cannot be trusted.
• **Eradicatice the root cause is patched (vendor-supplied fix or workarounds applied), restore services from known-good configurations, and perform heightened monitoring for post-remediation activity.
• Reporting and coordination: follow internal reporting procedures and share information with relevant parties, including vendor support and, where applicable, national incident reporting bodies like CISA or sector-specific ISACs.

These steps reflect CISA’s recommended practices for ICS incidents and mirror standard IR guidance adjusted for industrial environments where availability and safety are crucial.

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Conclusion​

CVE-2025-15577 in Valmet DNA Engineering Web Tools is a classic — but consequential — path traversal vulnerability: an unauthenticated file-read weakness that affects engineering web interfaces and can expose sensitive files and credentials. The vulnerability impacts Valmet DNA releases up to C2022 and has been elevated by multiple vulnerability trackers and a CISA advisory. Operators in energy and critical manufacturing should treat the issue as urgent: remove or restrict external exposure immediately, implement compensating network filters and WAF rules, harden logging and monitoring, and proceed with vendor-led patching and credential rotation after appropriate testing and change control.
History shows that path traversal in management UIs is a proven vector for deeper compromise in industrial environments. Practical defense is straightforward in concept — network isolation, strict access controls, robust monitoring, and quick application of vendor patches — but in operational settings these measures require precise coordination with engineering teams and careful change management. Start with isolation and logging today, and work with Valmet for an authenticated patch rollout and long-term hardening.

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Source: CISA Valmet DNA Engineering Web Tools | CISA