# Security

Rules that flag potential security flaws.
Table of Contents

## ApexBadCrypto

Since: PMD 5.5.3

Priority: Medium (3)

The rule makes sure you are using randomly generated IVs and keys for `Crypto` calls. Hard-wiring these values greatly compromises the security of encrypted data.

This rule is defined by the following Java class: net.sourceforge.pmd.lang.apex.rule.security.ApexBadCryptoRule

Example(s):

    public without sharing class Foo {
        Blob hardCodedIV = Blob.valueOf('Hardcoded IV 123');
        Blob hardCodedKey = Blob.valueOf('0000000000000000');
        Blob data = Blob.valueOf('Data to be encrypted');
        Blob encrypted = Crypto.encrypt('AES128', hardCodedKey, hardCodedIV, data);
    }

Use this rule by referencing it:

    <rule ref="category/apex/security.xml/ApexBadCrypto" />

## ApexCRUDViolation

Since: PMD 5.5.3

Priority: Medium (3)

The rule validates you are checking for access permissions before a SOQL/SOSL/DML operation. Since Apex runs by default in system mode not having proper permissions checks results in escalation of privilege and may produce runtime errors. This check forces you to handle such scenarios.

Since Winter ‘23 (API Version 56) you can enforce user mode for database operations by using `WITH USER_MODE` in SOQL. This makes Apex to respect Field-level security (FLS) and object permissions of the running user. When using user mode, no violation is reported by this rule.

By default, the rule allows access checks can be performed using system Apex provisions such as `DescribeSObjectResult.isAccessible/Createable/etc.`, the SOQL `WITH SECURITY_ENFORCED` clause, or using the open source Force.com ESAPI class library. Because it is common to use authorization facades to assist with this task, the rule also allows configuration of regular expression-based patterns for the methods used to authorize each type of CRUD operation. These pattern are configured via the following properties:

- `createAuthMethodPattern`/`createAuthMethodTypeParamIndex` - a pattern for the method used for create authorization and an optional 0-based index of the parameter passed to that method that denotes the `SObjectType` being authorized for create.
- `readAuthMethodPattern`/`readAuthMethodTypeParamIndex` - a pattern for the method used for read authorization and an optional 0-based index of the parameter passed to that method that denotes the `SObjectType` being authorized for read.
- `updateAuthMethodPattern`/`updateAuthMethodTypeParamIndex` - a pattern for the method used for update authorization and an optional 0-based index of the parameter passed to that method that denotes the `SObjectType` being authorized for update.
- `deleteAuthMethodPattern`/`deleteAuthMethodTypeParamIndex` - a pattern for the method used for delete authorization and an optional 0-based index of the parameter passed to that method that denotes the `SObjectType` being authorized for delete.
- `undeleteAuthMethodPattern`/`undeleteAuthMethodTypeParamIndex` - a pattern for the method used for undelete authorization and an optional 0-based index of the parameter passed to that method that denotes the `SObjectType` being authorized for undelete.
- `mergeAuthMethodPattern`/`mergeAuthMethodTypeParamIndex` - a pattern for the method used for merge authorization and an optional 0-based index of the parameter passed to that method that denotes the `SObjectType` being authorized for merge.

The following example shows how the rule can be configured for the sirono-common `AuthorizationUtil` class:

    <rule ref="category/apex/security.xml/ApexCRUDViolation" message="Validate CRUD permission before SOQL/DML operation">
        <priority>3</priority>
        <properties>
            <property name="createAuthMethodPattern" value="AuthorizationUtil\.(is|assert)(Createable|Upsertable)"/>
            <property name="readAuthMethodPattern" value="AuthorizationUtil\.(is|assert)Accessible"/>
            <property name="updateAuthMethodPattern" value="AuthorizationUtil\.(is|assert)(Updateable|Upsertable)"/>
            <property name="deleteAuthMethodPattern" value="AuthorizationUtil\.(is|assert)Deletable"/>
            <property name="undeleteAuthMethodPattern" value="AuthorizationUtil\.(is|assert)Undeletable"/>
            <property name="mergeAuthMethodPattern" value="AuthorizationUtil\.(is|assert)Mergeable"/>
        </properties>
    </rule>

Note: This rule will produce false positives for VF getter methods. In VF getters the access permission check happens automatically and is not needed explicitly. However, the rule can’t reliably determine whether a getter is a VF getter or not and reports a violation in any case. In such cases, the violation should be suppressed.

This rule is defined by the following Java class: net.sourceforge.pmd.lang.apex.rule.security.ApexCRUDViolationRule

Example(s):

    public class Foo {
        public Contact foo(String status, String ID) {

            // validate you can actually query what you intend to retrieve
            Contact c = [SELECT Status__c FROM Contact WHERE Id=:ID WITH SECURITY_ENFORCED];

            // Make sure we can update the database before even trying
            if (!Schema.sObjectType.Contact.fields.Status__c.isUpdateable()) {
                return null;
            }

            c.Status__c = status;
            update c;
            return c;
        }
    }

This rule has the following properties:

Name | Default Value | Description
--- | --- | ---
readAuthMethodPattern |  | A regular expression for one or more custom read authorization method name patterns.
readAuthMethodTypeParamIndex | 0 | The 0-based index of the sObjectType parameter for the custom read authorization method. Defaults to 0.
mergeAuthMethodPattern |  | A regular expression for one or more custom merge authorization method name patterns.
mergeAuthMethodTypeParamIndex | 0 | The 0-based index of the sObjectType parameter for the custom merge authorization method. Defaults to 0.
updateAuthMethodPattern |  | A regular expression for one or more custom update authorization method name patterns.
updateAuthMethodTypeParamIndex | 0 | The 0-based index of the sObjectType parameter for the custom update authorization method. Defaults to 0.
createAuthMethodPattern |  | A regular expression for one or more custom create authorization method name patterns.
createAuthMethodTypeParamIndex | 0 | The 0-based index of the sObjectType parameter for the custom create authorization method. Defaults to 0.
deleteAuthMethodPattern |  | A regular expression for one or more custom delete authorization method name patterns.
deleteAuthMethodTypeParamIndex | 0 | The 0-based index of the sObjectType parameter for the custom delete authorization method. Defaults to 0.
undeleteAuthMethodPattern |  | A regular expression for one or more custom undelete authorization method name patterns.
undeleteAuthMethodTypeParamIndex | 0 | The 0-based index of the sObjectType parameter for the custom undelete authorization method. Defaults to 0.

Use this rule with the default properties by just referencing it:

    <rule ref="category/apex/security.xml/ApexCRUDViolation" />

Use this rule and customize it:

    <rule ref="category/apex/security.xml/ApexCRUDViolation">
        <properties>
            <property name="readAuthMethodPattern" value="" />
            <property name="readAuthMethodTypeParamIndex" value="0" />
            <property name="mergeAuthMethodPattern" value="" />
            <property name="mergeAuthMethodTypeParamIndex" value="0" />
            <property name="updateAuthMethodPattern" value="" />
            <property name="updateAuthMethodTypeParamIndex" value="0" />
            <property name="createAuthMethodPattern" value="" />
            <property name="createAuthMethodTypeParamIndex" value="0" />
            <property name="deleteAuthMethodPattern" value="" />
            <property name="deleteAuthMethodTypeParamIndex" value="0" />
            <property name="undeleteAuthMethodPattern" value="" />
            <property name="undeleteAuthMethodTypeParamIndex" value="0" />
        </properties>
    </rule>

## ApexDangerousMethods

Since: PMD 5.5.3

Priority: Medium (3)

Checks against calling dangerous methods.

For the time being, it reports:

- Against `FinancialForce`’s `Configuration.disableTriggerCRUDSecurity()`. Disabling CRUD security opens the door to several attacks and requires manual validation, which is unreliable.
- Calling `System.debug` passing sensitive data as parameter, which could lead to exposure of private data.

This rule is defined by the following Java class: net.sourceforge.pmd.lang.apex.rule.security.ApexDangerousMethodsRule

Example(s):

    public class Foo {
        public Foo() {
            Configuration.disableTriggerCRUDSecurity();
        }
    }

Use this rule by referencing it:

    <rule ref="category/apex/security.xml/ApexDangerousMethods" />

## ApexInsecureEndpoint

Since: PMD 5.5.3

Priority: Medium (3)

Checks against accessing endpoints under plain http. You should always use https for security.

This rule is defined by the following Java class: net.sourceforge.pmd.lang.apex.rule.security.ApexInsecureEndpointRule

Example(s):

    public without sharing class Foo {
        void foo() {
            HttpRequest req = new HttpRequest();
            req.setEndpoint('http://localhost:com');
        }
    }

Use this rule by referencing it:

    <rule ref="category/apex/security.xml/ApexInsecureEndpoint" />

## ApexOpenRedirect

Since: PMD 5.5.3

Priority: Medium (3)

Checks against redirects to user-controlled locations. This prevents attackers from redirecting users to phishing sites.

This rule is defined by the following Java class: net.sourceforge.pmd.lang.apex.rule.security.ApexOpenRedirectRule

Example(s):

    public without sharing class Foo {
        String unsafeLocation = ApexPage.getCurrentPage().getParameters.get('url_param');
        PageReference page() {
           return new PageReference(unsafeLocation);
        }
    }

Use this rule by referencing it:

    <rule ref="category/apex/security.xml/ApexOpenRedirect" />

## ApexSharingViolations

Since: PMD 5.5.3

Priority: Medium (3)

Detect classes declared without explicit sharing mode if DML methods are used. This forces the developer to take access restrictions into account before modifying objects.

This rule is defined by the following Java class: net.sourceforge.pmd.lang.apex.rule.security.ApexSharingViolationsRule

Example(s):

    public without sharing class Foo {
        // DML operation here
    }

Use this rule by referencing it:

    <rule ref="category/apex/security.xml/ApexSharingViolations" />

## ApexSOQLInjection

Since: PMD 5.5.3

Priority: Medium (3)

Detects the usage of untrusted / unescaped variables in DML queries.

This rule is defined by the following Java class: net.sourceforge.pmd.lang.apex.rule.security.ApexSOQLInjectionRule

Example(s):

    public class Foo {
        public void test1(String t1) {
            Database.query('SELECT Id FROM Account' + t1);
        }
    }

Use this rule by referencing it:

    <rule ref="category/apex/security.xml/ApexSOQLInjection" />

## ApexSuggestUsingNamedCred

Since: PMD 5.5.3

Priority: Medium (3)

Detects hardcoded credentials used in requests to an endpoint.

You should refrain from hardcoding credentials:

- They are hard to maintain by being mixed in application code
- Particularly hard to update them when used from different classes
- Granting a developer access to the codebase means granting knowledge of credentials, keeping a two-level access is not possible.
- Using different credentials for different environments is troublesome and error-prone.

Instead, you should use Named Credentials and a callout endpoint.

For more information, you can check this

This rule is defined by the following Java class: net.sourceforge.pmd.lang.apex.rule.security.ApexSuggestUsingNamedCredRule

Example(s):

    public class Foo {
        public void foo(String username, String password) {
            Blob headerValue = Blob.valueOf(username + ':' + password);
            String authorizationHeader = 'BASIC ' + EncodingUtil.base64Encode(headerValue);
            req.setHeader('Authorization', authorizationHeader);
        }
    }

Use this rule by referencing it:

    <rule ref="category/apex/security.xml/ApexSuggestUsingNamedCred" />

## ApexXSSFromEscapeFalse

Since: PMD 5.5.3

Priority: Medium (3)

Reports on calls to `addError` with disabled escaping. The message passed to `addError` will be displayed directly to the user in the UI, making it prime ground for XSS attacks if unescaped.

This rule is defined by the following Java class: net.sourceforge.pmd.lang.apex.rule.security.ApexXSSFromEscapeFalseRule

Example(s):

    public without sharing class Foo {
        Trigger.new[0].addError(vulnerableHTMLGoesHere, false);
    }

Use this rule by referencing it:

    <rule ref="category/apex/security.xml/ApexXSSFromEscapeFalse" />

## ApexXSSFromURLParam

Since: PMD 5.5.3

Priority: Medium (3)

Makes sure that all values obtained from URL parameters are properly escaped / sanitized to avoid XSS attacks.

This rule is defined by the following Java class: net.sourceforge.pmd.lang.apex.rule.security.ApexXSSFromURLParamRule

Example(s):

    public without sharing class Foo {
        String unescapedstring = ApexPage.getCurrentPage().getParameters.get('url_param');
        String usedLater = unescapedstring;
    }

Use this rule by referencing it:

    <rule ref="category/apex/security.xml/ApexXSSFromURLParam" />