OrchardCMS/OrchardCore · error · AntivirusScanningException

The ClamAV antivirus scanner is enabled but the connection…

Error message

The ClamAV antivirus scanner is enabled but the connection timeout must be greater than zero.

What it means

ValidateOptions requires ConnectTimeoutSeconds > 0 when ClamAV is enabled. A non-positive value throws this AntivirusScanningException on the first scanned upload, since a zero/negative connect timeout is meaningless for the TCP connection.

Solutions

Set ConnectTimeoutSeconds to a positive value, e.g. 30.
Audit the ClamAV options block for omitted numeric fields binding to 0.
Validate options at startup so misconfiguration surfaces before uploads.
Document required options in your deployment config templates.

Example fix

// before
options.ConnectTimeoutSeconds = 0;
// after
options.ConnectTimeoutSeconds = 30;

Defensive patterns

Strategy: validation

Validate before calling

if (options.ConnectTimeoutSeconds <= 0)
    throw new InvalidOperationException("ClamAV ConnectTimeoutSeconds must be greater than zero.");

Try / catch

try
{
    await UploadFileAsync(stream);
}
catch (AntivirusScanningException ex) when (ex.Message.Contains("connection timeout"))
{
    // fix configuration before accepting uploads
}

Prevention

Set all ClamAV timeout options explicitly in every environment.
Use IValidateOptions/ValidateOnStart to fail fast.
Never use 0 to mean 'infinite' — the validator requires > 0.

When it happens

Trigger: Antivirus feature enabled, file uploaded, and ClamAvOptions.ConnectTimeoutSeconds is 0 (unset default) or negative in configuration.

Common situations: Configuring only Host/Port and assuming timeouts have sane defaults, a binding failure leaving 0, or someone setting 0 to mean 'no timeout' when >0 is required.

Understand the failure class

Background: "Invalid value" and "allowed values are" config errors: what your library rejected and how to fix it — this error's family across 41 libraries.

Timeouts: ETIMEDOUT, deadlines, and hung requests — what actually expires when a request times out.

Related errors

AI-assisted analysis of OrchardCMS/OrchardCore@4306c0717f (2026-09-13). Data as JSON: /api/errors/4cf4be9f38dafc3d. Report an issue: GitHub.

Appendix: source

Thrown at src/OrchardCore.Modules/OrchardCore.Antivirus/ClamAV/ClamAvFileEventHandler.cs:174

        throw new AntivirusScanningException(
            $"The ClamAV antivirus scanner returned an unexpected response while scanning '{context.FileName}': {response}");
    }

    private void ValidateOptions()
    {
        if (string.IsNullOrWhiteSpace(_options.Host))
        {
            throw new AntivirusScanningException("The ClamAV antivirus scanner is enabled but the host setting is missing.");
        }

        if (_options.Port is < 1 or > 65535)
        {
            throw new AntivirusScanningException("The ClamAV antivirus scanner is enabled but the port setting is invalid.");
        }

        if (_options.ConnectTimeoutSeconds <= 0)
        {
            throw new AntivirusScanningException("The ClamAV antivirus scanner is enabled but the connection timeout must be greater than zero.");
        }

        if (_options.TransferTimeoutSeconds <= 0)
        {
            throw new AntivirusScanningException("The ClamAV antivirus scanner is enabled but the transfer timeout must be greater than zero.");
        }
    }
}

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