PluginScore

Duplicate Killer – Prevent Duplicate Form Submissions

Block duplicate form submissions by validating unique email, phone and text fields — without CAPTCHA.

v1.6.6NIAUpdated Added 1k+ installs100% rating
contact form 7duplicate submissionsduplicate-orderselementor formswoocommerce
39
Score
57
Errors
103
Warnings
+0
Change

Category Scores

Security0
Repo100
Performance100
Maintainability68

Issues to Review

Prioritized issue groups from the latest Plugin Check scan

160 findings

Security

79

8 issue groups

Maintainability

76

13 issue groups

I18n

5

1 issue group

WARNINGMaintainabilityNon-prefixed global variableGlobal variables defined by a theme/plugin should start with the theme/plugin prefix. Found: "$active_form_name".48
Category
Maintainability
Occurrences
48
Severity
warning

Sample message

Global variables defined by a theme/plugin should start with the theme/plugin prefix. Found: "$active_form_name".

WordPress.NamingConventions.PrefixAllGlobals.NonPrefixedVariableFound
ERRORSecuritySQL query is not preparedUse placeholders and $wpdb->prepare(); found $prepared27
Category
Security
Occurrences
27
Severity
error

Sample message

Use placeholders and $wpdb->prepare(); found $prepared

WordPress.DB.PreparedSQL.NotPrepared
WARNINGSecurityInterpolated SQL is not preparedUse placeholders and $wpdb->prepare(); found interpolated variable $placeholders at \t\t\t WHERE form_plugin IN ($placeholders)\r\n13
Category
Security
Occurrences
13
Severity
warning

Sample message

Use placeholders and $wpdb->prepare(); found interpolated variable $placeholders at \t\t\t WHERE form_plugin IN ($placeholders)\r\n

WordPress.DB.PreparedSQL.InterpolatedNotPrepared
WARNINGSecurityDatabase parameter is not escapedUnescaped parameter $prepared used in $wpdb->get_results()\n$prepared assigned unsafely at line 79.12
Category
Security
Occurrences
12
Severity
warning

Sample message

Unescaped parameter $prepared used in $wpdb->get_results()\n$prepared assigned unsafely at line 79.

PluginCheck.Security.DirectDB.UnescapedDBParameter
ERRORMaintainabilitywp function not compatible with requires wpFunction "str_contains()" requires WordPress 5.9.0, but your plugin minimum supported version is WordPress 5.2.0.12
Category
Maintainability
Occurrences
12
Severity
error

Sample message

Function "str_contains()" requires WordPress 5.9.0, but your plugin minimum supported version is WordPress 5.2.0.

wp_function_not_compatible_with_requires_wpReference
ERRORSecurityOutput is not escapedAll output should be run through an escaping function (see the Security sections in the WordPress Developer Handbooks), found '$disabled_attr'.11
Category
Security
Occurrences
11
Severity
error

Sample message

All output should be run through an escaping function (see the Security sections in the WordPress Developer Handbooks), found '$disabled_attr'.

WordPress.Security.EscapeOutput.OutputNotEscapedReference
WARNINGSecurityNonce verification recommendedProcessing form data without nonce verification.11
Category
Security
Occurrences
11
Severity
warning

Sample message

Processing form data without nonce verification.

WordPress.Security.NonceVerification.Recommended
ERRORI18nMissing Translators CommentA function call to __() with texts containing placeholders was found, but was not accompanied by a "translators:" comment on the line above to clarify the meaning of the placeholders.5
Category
I18n
Occurrences
5
Severity
error

Sample message

A function call to __() with texts containing placeholders was found, but was not accompanied by a "translators:" comment on the line above to clarify the meaning of the placeholders.

WordPress.WP.I18n.MissingTranslatorsCommentReference
WARNINGMaintainabilityNo CachingDirect database call without caching detected. Consider using wp_cache_get() / wp_cache_set() or wp_cache_delete().4
Category
Maintainability
Occurrences
4
Severity
warning

Sample message

Direct database call without caching detected. Consider using wp_cache_get() / wp_cache_set() or wp_cache_delete().

WordPress.DB.DirectDatabaseQuery.NoCaching
WARNINGSecurityMissing nonce verificationProcessing form data without nonce verification.3
Category
Security
Occurrences
3
Severity
warning

Sample message

Processing form data without nonce verification.

WordPress.Security.NonceVerification.Missing
Show 12 more
WARNINGMaintainabilitySchema Change2
Category
Maintainability
Occurrences
2
Severity
warning

Sample message

Attempting a database schema change is discouraged.

WordPress.DB.DirectDatabaseQuery.SchemaChange
WARNINGMaintainabilityNon-prefixed constant2
Category
Maintainability
Occurrences
2
Severity
warning

Sample message

Global constants defined by a theme/plugin should start with the theme/plugin prefix. Found: "DK_NINJA_FORMS".

WordPress.NamingConventions.PrefixAllGlobals.NonPrefixedConstantFound
WARNINGMaintainabilityMixed line endings1
Category
Maintainability
Occurrences
1
Severity
warning

Sample message

File has mixed line endings; this may cause incorrect results

Internal.LineEndings.Mixed
ERRORSecurityDatabase parameter is not escaped1
Category
Security
Occurrences
1
Severity
error

Sample message

Unescaped parameter $sql used in $wpdb->get_results()\n$sql assigned unsafely at line 195.

PluginCheck.Security.DirectDB.UnescapedDBParameter
WARNINGMaintainabilityDirect Query1
Category
Maintainability
Occurrences
1
Severity
warning

Sample message

Use of a direct database call is discouraged.

WordPress.DB.DirectDatabaseQuery.DirectQuery
WARNINGSecurityUnfinished Prepare1
Category
Security
Occurrences
1
Severity
warning

Sample message

Replacement variables found, but no valid placeholders found in the query.

WordPress.DB.PreparedSQLPlaceholders.UnfinishedPrepare
WARNINGMaintainabilityslow db query meta key1
Category
Maintainability
Occurrences
1
Severity
warning

Sample message

Detected usage of meta_key, possible slow query.

WordPress.DB.SlowDBQuery.slow_db_query_meta_key
WARNINGMaintainabilityslow db query meta query1
Category
Maintainability
Occurrences
1
Severity
warning

Sample message

Detected usage of meta_query, possible slow query.

WordPress.DB.SlowDBQuery.slow_db_query_meta_query
WARNINGMaintainabilityNon-prefixed hook name1
Category
Maintainability
Occurrences
1
Severity
warning

Sample message

Hook names invoked by a theme/plugin should start with the theme/plugin prefix. Found: "duplicate_killer_database".

WordPress.NamingConventions.PrefixAllGlobals.NonPrefixedHooknameFound
WARNINGMaintainabilityerror log print r1
Category
Maintainability
Occurrences
1
Severity
warning

Sample message

print_r() found. Debug code should not normally be used in production.

WordPress.PHP.DevelopmentFunctions.error_log_print_r
WARNINGMaintainabilitymismatched plugin name1
Category
Maintainability
Occurrences
1
Severity
warning

Sample message

Plugin name "Duplicate Killer – Prevent Duplicate Form Submissions" is different from the name declared in plugin header "Duplicate Killer".

mismatched_plugin_nameReference
ERRORMaintainabilityMissing direct file access protection1
Category
Maintainability
Occurrences
1
Severity
error

Sample message

PHP file should prevent direct access. Add a check like: if ( ! defined( 'ABSPATH' ) ) exit;

missing_direct_file_access_protectionReference

External Connections

Potential connections found in static code analysis.

6 domains

Outbound calls

15

External assets

0

Incoming endpoints

0

Notable Domains

verselabwp.com10 · outbound
api.verselabwp.com1 · outbound
trustpilot.com1 · outbound

Platform / Reference Domains

gnu.org1 · platform/reference
profiles.wordpress.org1 · platform/reference
wordpress.org1 · platform/reference

External Asset Domains

No external asset domains detected.

Incoming Endpoints

No public endpoints detected.

Score History

2 score snapshots

+0
1007550250Jun 24, 2026, 08:18 PM UTC Score 39/100 Plugin v1.6.5 Plugin Check 2.0.0 57 errors, 103 warningsJun 26, 2026, 09:24 PM UTC Score 39/100 Plugin v1.6.6 Plugin Check 2.0.0 57 errors, 103 warningsJun 24, 2026Jun 26, 2026

v1.6.6

39

Latest

Findings
160
Errors
57
Warnings
103
Check
2.0.0

v1.6.5

39

Score

Findings
160
Errors
57
Warnings
103
Check
2.0.0

Relationship Map

Author, categories, issues, domains, and nearby plugins.

32 nodes

Author

NIAauthor

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