CVE-2025-2566
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedKaleris NAVIS N4 ULC (Ultra Light Client) contains an unsafe Java deserialization vulnerability. An unauthenticated attacker can make specially crafted requests to execute arbitrary code on the server.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · moderate confidenceKaleris NAVIS N4 ULC contains an unsafe Java deserialization vulnerability that allows unauthenticated attackers to execute arbitrary code via specially crafted network requests. This is a classic deserialization attack vector where malicious serialized objects are submitted to the application's deserialization endpoints, leading to remote code execution on the server.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- Authentication
- X
- User interaction
- None
- Scope
- X
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Confirm Kaleris NAVIS N4 ULC is installedSearch your systems for the presence of Kaleris NAVIS N4 ULC software. Check installed applications, program directories, or deployment inventory for this product.Affected if The product is found on your systems.
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Identify the installed versionLocate the version information for the installed Kaleris NAVIS N4 ULC instance. Check application logs, config files, or use vendor-provided version lookup methods. Compare your version against any patched versions provided by Kaleris.Affected if Your version is older than the patched version or you cannot determine the version.
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Check network exposureDetermine if the Kaleris NAVIS N4 ULC application ports or endpoints are exposed to untrusted networks. Review firewall rules, load balancer configurations, and network ACLs to assess whether the application accepts connections from outside your trusted network.Affected if The application is directly accessible from the internet or untrusted networks without authentication.
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Review application logs for deserialization activityExamine Kaleris NAVIS N4 ULC application logs and system logs for unusual Java deserialization patterns, unexpected serialized object submissions, or known attack signatures. Look for errors related to ObjectInputStream or class loading failures.Affected if Logs show evidence of deserialization exploitation attempts or unexpected deserialization activity.
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Check for indicators of compromiseInspect the host running Kaleris NAVIS N4 ULC for unauthorized processes, unusual scheduled tasks, newly created files, unexpected network connections, or shell scripts in temporary directories that may indicate remote code execution has occurred.Affected if Any suspicious artifacts or behaviors are found on the server hosting the application.
You are affected if Kaleris NAVIS N4 ULC is running in your environment and is accessible to unauthenticated attackers over the network.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataApply vendor-supplied patch or upgrade to a patched version of Kaleris NAVIS N4 ULC immediately. As an interim measure, consider network segmentation to restrict access to the affected component and implement WAF rules to detect deserialization attack patterns.
- Consultation4.0 h
- Implementation2.0 h
- Testing6.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2025-2566 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2025-2566 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data