CVE-2020-3927
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 · uneditedAn arbitrary-file-access vulnerability exists in ServiSign security plugin, as long as the attackers learn the specific API function, they may access arbitrary files on target system via crafted API parameter.
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 confidenceA path traversal vulnerability in the ServiSign security plugin allows remote attackers to access arbitrary files on the host system by manipulating an API parameter. The attacker must discover the specific vulnerable API function, then craft a request with directory traversal sequences (e.g., ../../) in the parameter to read files outside the intended web root.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data<= 1.0.19.0617CVSS 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
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- High
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
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 ServiSign installationLocate any ServiSign or Changingtec-related software components on the system, typically found in application directories or installed as a web plugin.Affected if ServiSign software from Changingtec is present on the system.
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Identify installed versionRetrieve the version number of the ServiSign installation using system inventory tools, installed programs list, or software documentation. Compare against the affected version range.Affected if The installed version is 1.0.19.0617 or any earlier version.
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Locate vulnerable API componentIdentify if the ServiSign security plugin API is exposed. Look for web-accessible endpoints or API functions associated with Servisign that handle file operations or parameter inputs.Affected if An API endpoint or function related to Servisign security plugin is accessible and accepts user-supplied input.
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Check API parameter handlingIf an API endpoint is accessible, inspect whether it processes file path parameters without strict validation. Look for parameters that might accept file or path references.Affected if The API accepts parameters that could contain directory traversal sequences like ../ without proper validation.
The environment is affected if Changingtec Servisign version 1.0.19.0617 or earlier is installed and exposes an API endpoint that processes file path parameters without validating directory traversal sequences.
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 dataImplement strict input validation and whitelist-based file access controls on the vulnerable API endpoint. Restrict file operations to allowed directories and remove or disable the unprotected API function if not essential.
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-3927 — 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-2020-3927 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
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