Remove PDF export

As we already decleared in earlier versions, this patch removes PDF
export entirely. It's a not acceptable security risk for every CodiMD
instance.

The current implementation allowed to extract arbitary files from the
CodiMD host and therefore leaking secrets from a `/etc/passwd` to
CodiMD's own config files and all secrets contained in it.

Thanks to Joona for finding this vulnerability in August last year,
which lead to an emergency disabling of PDF exports in 1.5.0.

Signed-off-by: Sheogorath <sheogorath@shivering-isles.com>
This commit is contained in:
Sheogorath 2020-02-26 14:52:55 +01:00
parent 37923d11f8
commit a2522888b2
No known key found for this signature in database
GPG key ID: C9B1C80737B9CE18
18 changed files with 5 additions and 99 deletions

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@ -127,10 +127,6 @@
"CMD_IMGUR_CLIENTID": {
"description": "Imgur API client id",
"required": false
},
"CMD_ALLOW_PDF_EXPORT": {
"description": "Enable or disable PDF exports",
"required": false
}
},
"addons": [

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@ -24,7 +24,6 @@ to `config.json` before filling in your own details.
| variables | example values | description |
| --------- | ------ | ----------- |
| `allowPDFExport` | `true` | Whether or not PDF export is offered. |
| `db` | `{ "dialect": "sqlite", "storage": "./db.codimd.sqlite" }` | set the db configs, [see more here](http://sequelize.readthedocs.org/en/latest/api/sequelize/) |
| `dbURL` | `mysql://localhost:3306/database` | Set the db in URL style. If set, then the relevant `db` config entries will be overridden. |
| `forbiddenNoteIDs` | `['robots.txt']` | disallow creation of notes, even if `allowFreeUrl` is `true` |

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@ -28,7 +28,6 @@ defaultNotePath can't be set from env-vars
| variable | example value | description |
| -------- | ------------- | ----------- |
| `CMD_ALLOW_PDF_EXPORT` | `true` or `false` | Enable or disable PDF exports |
| `CMD_CONFIG_FILE` | `/path/to/config.json` | optional override for the path to CodiMD's config file |
| `CMD_DB_URL` | `mysql://localhost:3306/database` | Set the db in URL style. If set, then the relevant `db` config entries will be overridden. |
| `CMD_LOGLEVEL` | `info`, `debug` ... | Defines what kind of logs are provided to stdout. |

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@ -13,7 +13,6 @@ You have to replace _\<NOTE\>_ with either the alias or id of a note you want to
| `/new` | `POST` | **Imports some markdown data into a new note.**<br>A random id will be assigned and the content will equal to the body of the received HTTP-request. The `Content-Type: text/markdown` header should be set on this request. |
| `/new/<ALIAS>` | `POST` | **Imports some markdown data into a new note with a given alias.**<br>This endpoint equals to the above one except that the alias from the url will be assigned to the note if [FreeURL-mode](../configuration-env-vars.md#users-and-privileges) is enabled. |
| `/<NOTE>/download` or `/s/<SHORT-ID>/download` | `GET` | **Returns the raw markdown content of a note.** |
| `/<NOTE>/pdf` | `GET` | **Returns a generated pdf version of the note.**<br>If pdf-support is disabled, a HTTP 403 will be returned.<br>_Please note: Currently pdf export is disabled generally because of a security problem with it._ |
| `/<NOTE>/publish` | `GET` | **Redirects to the published version of the note.** |
| `/<NOTE>/slide` | `GET` | **Redirects to the slide-presentation of the note.**<br>This is only useful on notes which are designed to be slides. |
| `/<NOTE>/info` | `GET` | **Returns metadata about the note.**<br>This includes the title and description of the note as well as the creation date and viewcount. The data is returned as a JSON object. |

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@ -89,29 +89,6 @@ paths:
'text/plain':
example: my-note
/{note}/pdf:
get:
tags:
- note
summary: Returns a generated pdf version of the note.
description: 'If pdf-support is disabled, a HTTP 403 will be returned.<br>_Please note: Currently pdf export is disabled generally because of a security problem with it._'
responses:
200:
description: The generated pdf version of the note
content:
'application/pdf':
example: binary
404:
description: Note does not exist
parameters:
- name: note
in: path
required: true
description: The note which should be exported as pdf
content:
'text/plain':
example: my-note
/{note}/publish:
get:
tags:

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@ -2,7 +2,7 @@ LinuxServer.io CodiMD Image
===
[![LinuxServer.io Discord](https://img.shields.io/discord/354974912613449730.svg?logo=discord&label=LSIO%20Discord&style=flat-square)](https://discord.gg/YWrKVTn)[![container version badge](https://images.microbadger.com/badges/version/linuxserver/codimd.svg)](https://microbadger.com/images/linuxserver/codimd "Get your own version badge on microbadger.com")[![container image size badge](https://images.microbadger.com/badges/image/linuxserver/codimd.svg)](https://microbadger.com/images/linuxserver/codimd "Get your own version badge on microbadger.com")![Docker Pulls](https://img.shields.io/docker/pulls/linuxserver/codimd.svg)![Docker Stars](https://img.shields.io/docker/stars/linuxserver/codimd.svg)[![Build Status](https://ci.linuxserver.io/buildStatus/icon?job=Docker-Pipeline-Builders/docker-codimd/master)](https://ci.linuxserver.io/job/Docker-Pipeline-Builders/job/docker-codimd/job/master/)[![LinuxServer.io CI summary](https://lsio-ci.ams3.digitaloceanspaces.com/linuxserver/codimd/latest/badge.svg)](https://lsio-ci.ams3.digitaloceanspaces.com/linuxserver/codimd/latest/index.html)
[LinuxServer.io](https://linuxserver.io) have created an Ubuntu-based multi-arch container image for x86-64, arm64 and armhf which supports PDF export from all architectures using [PhantomJS](https://phantomjs.org/).
[LinuxServer.io](https://linuxserver.io) have created an Ubuntu-based multi-arch container image for x86-64, arm64 and armhf.
- It supports all the environment variables detailed in the [configuration documentation](../configuration-env-vars.md) to modify it according to your needs.

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@ -182,7 +182,6 @@ app.locals.serverURL = config.serverURL
app.locals.sourceURL = config.sourceURL
app.locals.allowAnonymous = config.allowAnonymous
app.locals.allowAnonymousEdits = config.allowAnonymousEdits
app.locals.allowPDFExport = config.allowPDFExport
app.locals.authProviders = {
facebook: config.isFacebookEnable,
twitter: config.isTwitterEnable,

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@ -153,7 +153,6 @@ module.exports = {
email: true,
allowEmailRegister: true,
allowGravatar: true,
allowPDFExport: true,
openID: false,
// linkifyHeaderStyle - How is a header text converted into a link id.
// Header Example: "3.1. Good Morning my Friend! - Do you have 5$?"

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@ -129,7 +129,6 @@ module.exports = {
email: toBooleanConfig(process.env.CMD_EMAIL),
allowEmailRegister: toBooleanConfig(process.env.CMD_ALLOW_EMAIL_REGISTER),
allowGravatar: toBooleanConfig(process.env.CMD_ALLOW_GRAVATAR),
allowPDFExport: toBooleanConfig(process.env.CMD_ALLOW_PDF_EXPORT),
openID: toBooleanConfig(process.env.CMD_OPENID),
linkifyHeaderStyle: process.env.CMD_LINKIFY_HEADER_STYLE
}

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@ -115,6 +115,5 @@ module.exports = {
}
},
email: toBooleanConfig(process.env.HMD_EMAIL),
allowEmailRegister: toBooleanConfig(process.env.HMD_ALLOW_EMAIL_REGISTER),
allowPDFExport: toBooleanConfig(process.env.HMD_ALLOW_PDF_EXPORT)
allowEmailRegister: toBooleanConfig(process.env.HMD_ALLOW_EMAIL_REGISTER)
}

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@ -119,7 +119,6 @@ config.isGitLabEnable = config.gitlab.clientID && config.gitlab.clientSecret
config.isLDAPEnable = config.ldap.url
config.isSAMLEnable = config.saml.idpSsoUrl
config.isOAuth2Enable = config.oauth2.clientID && config.oauth2.clientSecret
config.isPDFExportEnable = config.allowPDFExport
// Check gitlab api version
if (config.gitlab && config.gitlab.version !== 'v4' && config.gitlab.version !== 'v3') {
@ -188,12 +187,6 @@ switch (config.imageUploadType) {
]
}
// Disable PDF export due to security issue
if (config.allowPDFExport) {
config.allowPDFExport = false
logger.warn('PDF export was disabled for this release to mitigate a critical security issue. This feature will hopefully become available again in future releases.')
}
// generate correct path
config.sslCAPath.forEach(function (capath, i, array) {
array[i] = path.resolve(appRootPath, capath)

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@ -37,6 +37,5 @@ module.exports = {
// document
documentmaxlength: undefined,
imageuploadtype: undefined,
allowemailregister: undefined,
allowpdfexport: undefined
allowemailregister: undefined
}

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@ -4,7 +4,6 @@ const config = require('../../config')
const errors = require('../../errors')
const fs = require('fs')
const shortId = require('shortid')
const markdownpdf = require('markdown-pdf')
const moment = require('moment')
const querystring = require('querystring')
@ -33,37 +32,6 @@ exports.getInfo = function getInfo (req, res, note) {
res.send(data)
}
exports.createPDF = function createPDF (req, res, note) {
const url = config.serverURL || 'http://' + req.get('host')
const body = note.content
const extracted = models.Note.extractMeta(body)
let content = extracted.markdown
const title = models.Note.decodeTitle(note.title)
if (!fs.existsSync(config.tmpPath)) {
fs.mkdirSync(config.tmpPath)
}
const path = config.tmpPath + '/' + Date.now() + '.pdf'
content = content.replace(/\]\(\//g, '](' + url + '/')
markdownpdf().from.string(content).to(path, function () {
if (!fs.existsSync(path)) {
logger.error('PDF seems to not be generated as expected. File doesn\'t exist: ' + path)
return errors.errorInternalError(res)
}
const stream = fs.createReadStream(path)
let filename = title
// Be careful of special characters
filename = encodeURIComponent(filename)
// Ideally this should strip them
res.setHeader('Content-disposition', 'attachment; filename="' + filename + '.pdf"')
res.setHeader('Cache-Control', 'private')
res.setHeader('Content-Type', 'application/pdf; charset=UTF-8')
res.setHeader('X-Robots-Tag', 'noindex, nofollow') // prevent crawling
stream.pipe(res)
fs.unlinkSync(path)
})
}
exports.createGist = function createGist (req, res, note) {
const data = {
client_id: config.github.clientID,

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@ -111,14 +111,6 @@ export module NoteController {
case 'info':
noteActions.getInfo(req, res, note);
break;
case 'pdf':
if (config.allowPDFExport) {
noteActions.createPDF(req, res, note)
} else {
logger.error('PDF export failed: Disabled by config. Set "allowPDFExport: true" to enable. Check the documentation for details');
errors.errorForbidden(res)
}
break;
case 'gist':
noteActions.createGist(req, res, note);
break;

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@ -79,7 +79,6 @@
"markdown-it-regexp": "^0.4.0",
"markdown-it-sub": "^1.0.0",
"markdown-it-sup": "^1.0.0",
"markdown-pdf": "^10.0.0",
"mathjax": "~2.7.6",
"mermaid": "~8.4.6",
"meta-marked": "git+https://github.com/codimd/meta-marked#semver:^0.4.5",

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@ -941,8 +941,6 @@ ui.toolbar.download.rawhtml.click(function (e) {
e.stopPropagation()
exportToRawHTML(ui.area.markdown)
})
// pdf
ui.toolbar.download.pdf.attr('download', '').attr('href', noteurl + '/pdf')
// export to dropbox
ui.toolbar.export.dropbox.click(function () {
var filename = renderFilename(ui.area.markdown) + '.md'

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@ -17,8 +17,7 @@ export const getUIElements = () => ({
download: {
markdown: $('.ui-download-markdown'),
html: $('.ui-download-html'),
rawhtml: $('.ui-download-raw-html'),
pdf: $('.ui-download-pdf-beta')
rawhtml: $('.ui-download-raw-html')
},
export: {
dropbox: $('.ui-save-dropbox'),

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@ -63,10 +63,6 @@
</li>
<li role="presentation"><a role="menuitem" class="ui-download-raw-html" tabindex="-1" href="#" target="_self"><i class="fa fa-file-code-o fa-fw"></i> <%= __('Raw HTML') %></a>
</li>
<% if(typeof allowPDFExport !== 'undefined' && allowPDFExport) {%>
<li role="presentation"><a role="menuitem" class="ui-download-pdf-beta" tabindex="-1" href="#" target="_self"><i class="fa fa-file-pdf-o fa-fw"></i> PDF (Beta)</a>
</li>
<% } %>
<li class="divider"></li>
<li role="presentation"><a role="menuitem" class="ui-help" href="#" data-toggle="modal" data-target=".help-modal"><i class="fa fa-question-circle fa-fw"></i> Help</a>
</li>
@ -162,10 +158,6 @@
</li>
<li role="presentation"><a role="menuitem" class="ui-download-raw-html" tabindex="-1" href="#" target="_self"><i class="fa fa-file-code-o fa-fw"></i> <%= __('Raw HTML') %></a>
</li>
<% if(typeof allowPDFExport !== 'undefined' && allowPDFExport) {%>
<li role="presentation"><a role="menuitem" class="ui-download-pdf-beta" tabindex="-1" href="#" target="_self"><i class="fa fa-file-pdf-o fa-fw"></i> PDF (Beta)</a>
</li>
<% } %>
</ul>
</li>
</ul>