### audit-filter

[![crates.io version](https://img.shields.io/crates/v/audit-filter.svg)](https://img.shields.io/crates/v/audit-filter.svg)
[![Build Status](https://travis-ci.org/mozilla-services/audit-filter.svg?branch=master)](https://travis-ci.org/mozilla-services/audit-filter)
[![npm version](https://badge.fury.io/js/audit-filter.svg)](https://badge.fury.io/js/audit-filter)

`audit-filter` takes the output of [`npm audit
--json`](https://docs.npmjs.com/cli/audit) and an
[nsp](https://github.com/nodesecurity/nsp) rc config file [*without
comments*](#fixing-comments-in-nsprc-files) and filters out advisories
according to the nsp offline exceptions format (see usage for an
example).

This provides a migration path from `nsp check` to `npm audit` and
lets projects to use `npm audit` in CI pipelines without masking all
advisories (e.g. with `npm audit || true`).

### Install

#### Requirements

* node 8.x or 10.x
* npm@6 (for `--json` support and newer package-lock.json format)

#### Local NPM package

1. Run `npm install --save-dev audit-filter` to add it as a dev dependency

1. Require an npm version with `npm audit` support in `package.json` e.g.

```json
{
  ...
  "engines": {
    "node": ">=8",
    "npm": ">=6.4.1"
  },
  ...
}
```

1. Add an empty exceptions file named `.nsprc`:


```json
{
  "exceptions": [
  ]
}
```

1. Optionally, add an npm script command:

```json
{
  "scripts": {
    "lint:deps": "npm audit --json | audit-filter --nsp-config=.nsprc --audit=-"
	...
  }
  ...
  "devDependencies": {
    "audit-filter": "0.3.0"
  },
  ...
}
```

and test it with: `npm run lint:deps` or `npm run-script lint:deps`

1. Optionally, set "The minimum level of vulnerability for npm audit to exit with a non-zero exit with [`npm config audit level ('low', 'moderate', 'high', 'critical')`](https://docs.npmjs.com/misc/config#audit-level)

#### Global NPM package

```console
npm install -g audit-filter
```

#### Cargo

```console
cargo install audit-filter
```

### Usage

Note: all commands run from the project root

```console
$ audit-filter -h
audit-filter filters the output of "npm audit --json"

Usage:
  audit-filter [--json] [--audit=<->] [--nsp-config=<.nsprc>]
  audit-filter (-h | --help | --version)

Options:
  -h --help                       Show this screen.
  --version                       Show version.
  --json                          Output subset of JSON for the unfiltered advisories as an array.
  --audit=<audit>                 NPM Audit JSON file [default: -].
  --nsp-config=<config>           Default filter config [default: .nsprc].
$ cd audit-filter/example/
$ cat package.json
{
  "dependencies": {
    "moment": "2.19.2",
    "restify": "7.0.0"
  },
  "devDependencies": {
    "audit-filter": "0.3.0",
    "lodash": "^4.0.0"
  },
  "engines": {
    "node": ">=8",
    "npm": ">=6.4.1"
  },
  "scripts": {
    "lint:deps": "npm audit --json | audit-filter --nsp-config=.nsprc --audit=-"
  }
}
$ npm --version
6.7.0
$ npm audit
                                                                                
                       === npm audit security report ===                        
                                                                                
# Run  npm install moment@2.24.0  to resolve 1 vulnerability
┌───────────────┬──────────────────────────────────────────────────────────────┐
│ Low           │ Regular Expression Denial of Service                         │
├───────────────┼──────────────────────────────────────────────────────────────┤
│ Package       │ moment                                                       │
├───────────────┼──────────────────────────────────────────────────────────────┤
│ Dependency of │ moment                                                       │
├───────────────┼──────────────────────────────────────────────────────────────┤
│ Path          │ moment                                                       │
├───────────────┼──────────────────────────────────────────────────────────────┤
│ More info     │ https://npmjs.com/advisories/532                             │
└───────────────┴──────────────────────────────────────────────────────────────┘


# Run  npm install --save-dev lodash@4.17.11  to resolve 1 vulnerability
┌───────────────┬──────────────────────────────────────────────────────────────┐
│ Low           │ Prototype Pollution                                          │
├───────────────┼──────────────────────────────────────────────────────────────┤
│ Package       │ lodash                                                       │
├───────────────┼──────────────────────────────────────────────────────────────┤
│ Dependency of │ lodash [dev]                                                 │
├───────────────┼──────────────────────────────────────────────────────────────┤
│ Path          │ lodash                                                       │
├───────────────┼──────────────────────────────────────────────────────────────┤
│ More info     │ https://npmjs.com/advisories/577                             │
└───────────────┴──────────────────────────────────────────────────────────────┘


# Run  npm update moment --depth 3  to resolve 1 vulnerability
┌───────────────┬──────────────────────────────────────────────────────────────┐
│ Low           │ Regular Expression Denial of Service                         │
├───────────────┼──────────────────────────────────────────────────────────────┤
│ Package       │ moment                                                       │
├───────────────┼──────────────────────────────────────────────────────────────┤
│ Dependency of │ restify                                                      │
├───────────────┼──────────────────────────────────────────────────────────────┤
│ Path          │ restify > bunyan > moment                                    │
├───────────────┼──────────────────────────────────────────────────────────────┤
│ More info     │ https://npmjs.com/advisories/532                             │
└───────────────┴──────────────────────────────────────────────────────────────┘


found 3 low severity vulnerabilities in 137 scanned packages
  run `npm audit fix` to fix 3 of them.
$ echo $?
1
$ cat .nsprc
{
  "exceptions": [
    "https://npmjs.com/advisories/532",
    "https://npmjs.com/advisories/577"
   ]
}
$ npm audit --json | audit-filter
No advisories found after filtering.
$ echo $?
0
$ # Alternatively specify audit and config file paths (note: errors print to stderr)
$ cd .. && audit-filter --nsp-config tests/fixtures/screenshots-0191b17d3bac5de51efa7acbaa0d52bb26c91573-nsprc.json --audit tests/fixtures/screenshots-0191b17d3bac5de51efa7acbaa0d52bb26c91573-npm-6.4.1-audit.json
Unfiltered advisories:
  https://nodesecurity.io/advisories/118
  https://nodesecurity.io/advisories/534
  https://nodesecurity.io/advisories/681
$ echo $?
1
$ # use --json for JSON output
$ audit-filter --json --nsp-config tests/fixtures/screenshots-0191b17d3bac5de51efa7acbaa0d52bb26c91573-nsprc.json --audit tests/fixtures/screenshots-0191b17d3bac5de51efa7acbaa0d52bb26c91573-npm-6.4.1-audit.json
[
  {
    "findings": [
      {
        "version": "2.0.10",
        "paths": [
          "istanbul-middleware>archiver>glob>minimatch"
        ],
        "dev": true,
        "optional": false,
        "bundled": false
      }
    ],
    "id": 118,
    "title": "Regular Expression Denial of Service",
    "module_name": "minimatch",
    "overview": "Affected versions of `minimatch` are vulnerable to regular expression denial of service attacks when user input is passed into the `pattern` argument of `minimatch(path, pattern)`.\n\n\n## Proof of Concept\n```\nvar minimatch = require(“minimatch”);\n\n// utility function for generating long strings\nvar genstr = function (len, chr) {\n  var result = “”;\n  for (i=0; i<=len; i++) {\n    result = result + chr;\n  }\n  return result;\n}\n\nvar exploit = “[!” + genstr(1000000, “\\\\”) + “A”;\n\n// minimatch exploit.\nconsole.log(“starting minimatch”);\nminimatch(“foo”, exploit);\nconsole.log(“finishing minimatch”);\n```",
    "recommendation": "Update to version 3.0.2 or later.",
    "severity": "high",
    "url": "https://nodesecurity.io/advisories/118"
  },
  {
    "findings": [
      {
        "version": "2.2.0",
        "paths": [
          "istanbul-middleware>body-parser>debug"
        ],
        "dev": true,
        "optional": false,
        "bundled": false
      }
    ],
    "id": 534,
    "title": "Regular Expression Denial of Service",
    "module_name": "debug",
    "overview": "Affected versions of `debug` are vulnerable to regular expression denial of service when untrusted user input is passed into the `o` formatter. \n\nAs it takes 50,000 characters to block the event loop for 2 seconds, this issue is a low severity issue.",
    "recommendation": "Version 2.x.x: Update to version 2.6.9 or later.\nVersion 3.x.x: Update to version 3.1.0 or later.\n",
    "severity": "low",
    "url": "https://nodesecurity.io/advisories/534"
  },
  {
    "findings": [
      {
        "version": "0.4.7",
        "paths": [
          "jpm>firefox-profile>adm-zip",
          "web-ext>firefox-profile>adm-zip"
        ],
        "dev": false,
        "optional": false,
        "bundled": false
      }
    ],
    "id": 681,
    "title": "Arbitrary File Write via Archive Extraction",
    "module_name": "adm-zip",
    "overview": "Versions of `adm-zip` before 0.4.9 are vulnerable to arbitrary file write when used to extract a specifically crafted archive that contains path traversal filenames (`../../file.txt` for example).",
    "recommendation": "Update to version 0.4.9 or later.",
    "severity": "high",
    "url": "https://nodesecurity.io/advisories/681"
  }
]
```

### Fixing comments in .nsprc files

```console
$ cat tests/fixtures/screenshots-0191b17d3bac5de51efa7acbaa0d52bb26c91573-nsprc-comment.json
{
  // See https://github.com/mozilla-services/screenshots/issues/4397
  "exceptions": [
    "https://nodesecurity.io/advisories/566",
    "https://nodesecurity.io/advisories/577",
    "https://nodesecurity.io/advisories/598",
    "https://nodesecurity.io/advisories/663",
    "https://nodesecurity.io/advisories/664"
   ]
}
$ audit-filter --nsp-config tests/fixtures/screenshots-0191b17d3bac5de51efa7acbaa0d52bb26c91573-nsprc-comment.json --audit tests/fixtures/screenshots-0191b17d3bac5de51efa7acbaa0d52bb26c91573-npm-6.4.1-audit.json
Error parsing nsp config JSON: key must be a string at line 2 column 3
$ echo $?
2
$ cat tests/fixtures/screenshots-0191b17d3bac5de51efa7acbaa0d52bb26c91573-nsprc-comment.json | sed "s|// .*||g" | python -m json.tool
{
    "exceptions": [
        "https://nodesecurity.io/advisories/566",
        "https://nodesecurity.io/advisories/577",
        "https://nodesecurity.io/advisories/598",
        "https://nodesecurity.io/advisories/663",
        "https://nodesecurity.io/advisories/664"
    ]
}
$ # alternatively convert comments into valid JSON e.g.
{
  "comment": "See https://github.com/mozilla-services/screenshots/issues/4397",
  "exceptions": [
    "https://nodesecurity.io/advisories/566",
    "https://nodesecurity.io/advisories/577",
    "https://nodesecurity.io/advisories/598",
    "https://nodesecurity.io/advisories/663",
    "https://nodesecurity.io/advisories/664"
   ]
}
```

### Exit Codes

* 0 - No advisories or all advisories acked from filters
* 1 - New failures one or more unacked advisory. Rerun `npm audit` to see the errors.
* 2 - Error finding or parsing config files or audit JSON.

### Other errors

NB: error messages will differ for audit-filter installed with NPM

Enumerated here for completeness. These all exit with code 2.

#### Error opening audit file

```console
$ audit-filter --nsp-config tests/fixtures/screenshots-0191b17d3bac5de51efa7acbaa0d52bb26c91573-nsprc.json --audit no-file
Error opening audit JSON no-file: No such file or directory (os error 2)
```

#### Error parsing audit from stdin

```console
$ echo "this is not JSON" | audit-filter --nsp-config tests/fixtures/screenshots-0191b17d3bac5de51efa7acbaa0d52bb26c91573-nsprc.json --audit -
Error parsing audit JSON from stdin: expected ident at line 1 column 2
```

#### Error parsing audit from file

```console
$ echo "this is not JSON" > not_json.txt
$ audit-filter --nsp-config tests/fixtures/screenshots-0191b17d3bac5de51efa7acbaa0d52bb26c91573-nsprc.json --audit not_json.txt
Error parsing audit JSON: expected ident at line 1 column 2
```

#### Error opening nsp config file

```console
$ audit-filter --nsp-config no-file --audit tests/fixtures/screenshots-0191b17d3bac5de51efa7acbaa0d52bb26c91573-npm-6.4.1-audit.json
Error opening nsp config JSON no-file: No such file or directory (os error 2)
```

#### Error parsing nsp config from stdin

```console
$ echo "this is not JSON" | audit-filter --nsp-config - --audit tests/fixtures/screenshots-0191b17d3bac5de51efa7acbaa0d52bb26c91573-npm-6.4.1-audit.json
Error parsing nsp config JSON from stdin: expected ident at line 1 column 2
```

#### Error parsing nsp config from file

```console
$ echo "this is not JSON" > not_json.txt
$ audit-filter --nsp-config not_json.txt --audit tests/fixtures/screenshots-0191b17d3bac5de51efa7acbaa0d52bb26c91573-npm-6.4.1-audit.json
Error parsing nsp config JSON: expected ident at line 1 column 2
```

### Building

To build a static executable:

```console
$ rustup target add x86_64-unknown-linux-musl
...
$ cargo build --release --target x86_64-unknown-linux-musl
...
$ ls -lh ./target/x86_64-unknown-linux-musl/release/audit-filter
-rwxrwxr-x 2 gguthe gguthe 7.0M Sep 20 13:09 ./target/x86_64-unknown-linux-musl/release/audit-filter
$ ldd ./target/x86_64-unknown-linux-musl/release/audit-filter
        not a dynamic executable
```

### Contributors

* @agwells