(#) Application by default permits cleartext traffic !!! WARNING: Application by default permits cleartext traffic This is a warning. Id : `DefaultCleartextTraffic` Summary : Application by default permits cleartext traffic Severity : Warning Category : Security Platform : Android Vendor : Google - Android 3P Vulnerability Research Contact : https://github.com/google/android-security-lints Feedback : https://github.com/google/android-security-lints/issues Min : Lint 4.1 Compiled : Lint 8.0 and 8.1 Artifact : [com.android.security.lint:lint](com_android_security_lint_lint.md.html) Since : 1.0.1 Affects : Manifest files Editing : This check runs on the fly in the IDE editor See : https://goo.gle/DefaultCleartextTraffic Implementation : [Source Code](https://github.com/google/android-security-lints/tree/main/checks/src/main/java/com/example/lint/checks/MissingNetworkSecurityConfigDetector.kt) Tests : [Source Code](https://github.com/google/android-security-lints/tree/main/checks/src/test/java/com/example/lint/checks/MissingNetworkSecurityConfigDetectorTest.kt) Copyright Year : 2023 Apps targeting SDK versions earlier than 28 trust cleartext traffic by default. The application must explicitly opt out of this in order to only use secure connections. (##) Example Here is an example of lint warnings produced by this check: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~text AndroidManifest.xml:3:Warning: On SDK versions below 28, the application by default trusts cleartext traffic. Add a Network Security Config file to opt out of these insecure connections. [DefaultCleartextTraffic] <application> ----------- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Here is the source file referenced above: `AndroidManifest.xml`: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~xml linenumbers <manifest xmlns:android='http://schemas.android.com/apk/res/android' package='test.pkg'> <uses-sdk android:targetSdkVersion='27'/> <application> <activity android:name='com.example.MainActivity'></activity> </application> </manifest> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ You can also visit the [source code](https://github.com/google/android-security-lints/tree/main/checks/src/test/java/com/example/lint/checks/MissingNetworkSecurityConfigDetectorTest.kt) for the unit tests for this check to see additional scenarios. The above example was automatically extracted from the first unit test found for this lint check, `MissingNetworkSecurityConfigDetector.testWhenNoNetworkSecurityConfig_defaultCleartextTrafficSdkLevel_showsWarning`. To report a problem with this extracted sample, visit https://github.com/google/android-security-lints/issues. (##) Including !!! This is not a built-in check. To include it, add the below dependency to your project. This lint check is included in the lint documentation, but the Android team may or may not agree with its recommendations. ``` // build.gradle.kts lintChecks("com.android.security.lint:lint:1.0.3") // build.gradle lintChecks 'com.android.security.lint:lint:1.0.3' // build.gradle.kts with version catalogs: lintChecks(libs.com.android.security.lint.lint) # libs.versions.toml [versions] com-android-security-lint-lint = "1.0.3" [libraries] # For clarity and text wrapping purposes the following declaration is # shown split up across lines, but in TOML it needs to be on a single # line (see https://github.com/toml-lang/toml/issues/516) so adjust # when pasting into libs.versions.toml: com-android-security-lint-lint = { module = "com.android.security.lint:lint", version.ref = "com-android-security-lint-lint" } ``` 1.0.3 is the version this documentation was generated from; there may be newer versions available. [Additional details about com.android.security.lint:lint](com_android_security_lint_lint.md.html). (##) Suppressing You can suppress false positives using one of the following mechanisms: * Adding the suppression attribute `tools:ignore="DefaultCleartextTraffic"` on the problematic XML element (or one of its enclosing elements). You may also need to add the following namespace declaration on the root element in the XML file if it's not already there: `xmlns:tools="http://schemas.android.com/tools"`. ```xml <?xml version="1.0" encoding="UTF-8"?> <manifest xmlns:tools="http://schemas.android.com/tools"> ... <application tools:ignore="DefaultCleartextTraffic" .../> ... </manifest> ``` * Using a special `lint.xml` file in the source tree which turns off the check in that folder and any sub folder. A simple file might look like this: ```xml <?xml version="1.0" encoding="UTF-8"?> <lint> <issue id="DefaultCleartextTraffic" severity="ignore" /> </lint> ``` Instead of `ignore` you can also change the severity here, for example from `error` to `warning`. You can find additional documentation on how to filter issues by path, regular expression and so on [here](https://googlesamples.github.io/android-custom-lint-rules/usage/lintxml.md.html). * In Gradle projects, using the DSL syntax to configure lint. For example, you can use something like ```gradle lintOptions { disable 'DefaultCleartextTraffic' } ``` In Android projects this should be nested inside an `android { }` block. * For manual invocations of `lint`, using the `--ignore` flag: ``` $ lint --ignore DefaultCleartextTraffic ...` ``` * Last, but not least, using baselines, as discussed [here](https://googlesamples.github.io/android-custom-lint-rules/usage/baselines.md.html).