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Comment: actually add the policy link, existing link was about telemetry use
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Editor: PaulWise
Comment: file based version leakage
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   * XMMP clients leak this in resource names or the {{{Operating System}}} and or {{{Client}}} fields of responses to "Get Info" requests
     * These clients are definitely affected: bitlbee libpurple conversations profanity psi
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   * File format writing software leaks this into files
     * Inkscape leaks this into the `inkscape:version` attribute of the `svg` element of SVG files.
 * Some software leaks the local time or timezone
   * Probably almost all protocols and clients do this
   * Web browsers leak this to the {{{getTimezoneOffset()}}} JavaScript
     * All modern web browsers do this, less modern ones may or may not
   * XMMP clients leak this in the {{{Local Time}}} field of responses to "Get Info" requests
     * These clients are definitely affected: bitlbee libpurple psi
 * Some software leaks local paths
   * Inkscape leaks the local path to the exported PNG file into the `inkscape:export-filename` attribute of the `svg` element of SVG files.

Contents

  1. Documentation
  2. Detection tools
  3. Issue categories
  4. Reports
  5. Privacy issues in Debian packages
    1. Phone home
    2. Phone elsewhere
      1. Connectivity
      2. DNS
      3. ICE
    3. Data sharing
    4. Data leakage
    5. Data storage
    6. Telemetry libraries
    7. Logging
  6. See also

Documentation

Detection tools

Issue categories

  • logging & verbose logging

  • homephoning without user consent
    • cleartext
    • TLS
  • featurebug: when a bug is also a feature
  • privacy defaults
    • optin
    • optout
  • traceability
  • no deletion of config files when uninstalling a package
  • data leakage
    • software names and version numbers

Reports

Privacy issues in Debian packages

Phone home

There are some common categories of phoning home:

These packages either don't fit those categories or do lots of them and more:

Phone elsewhere

Connectivity

Some services need to know when system is "online". Best practice is to only rely on system services, optionally coupled with distro-specific public service like network-manager-config-connectivity-debian . An antipattern is to hardcode probing of a public service.

Packages determining connectivity by probing Apple website and Google DNS resolvers:

Packages determining connectivity by probing Google DNS resolvers:

DNS

Many network protocols need a nameserver. Best practice is to only rely on user input or system resolver. An antipattern is to hardcode one or more nameservers, either exclusively or as internal default.

Packages using Cloudflare and Freenom and Google DNS resolvers by default:

Packages using Cloudflare and Google DNS resolvers by default:

Packages using Cloudflare and Google and Qaud9 DNS resolvers by default:

Packages using Google DNS resolvers by default:

Packages using Google and UncensoredDNS DNS resolvers by default:

Packages using Google and 77.88.39.152 DNS resolvers by default:

ICE

WebRTC and SIP and similar protocols need a public-accessible TUN/STUN/TURN service across public networks. Best practice is to only rely on local configuration. an antipattern is to hardcode public STUN services, either exclusively or as internal default.

Packages using Ekiga STUN resolvers by default:

Packages using Ekiga and GNUnet and Mozilla STUN resolvers by default:

Packages using Ekiga and SIPgate and Stuntman and more STUN resolvers by default:

Packages using Ekiga and SIPphone and Google and Stuntman and Xten and more STUN resolvers by default:

Packages using Google STUN resolvers by default:

Packages using Google and Stuntman STUN resolvers by default:

Packages using SIPgate and SIPphone STUN resolvers by default:

Packages using SIPphone STUN resolvers by default:

Packages using Stuntman STUN resolvers by default:

Packages using Xten STUN resolvers by default:

Data sharing

  • remmina - shares the clipboard with remote hosts over RDP by default
  • pidgin - shares typing notifications with remote peers by default
  • hw-probe - includes truncated salted hashes of MAC addresses and serial numbers in hardware probe reports
  • git-remote-bzr (all implementations) - leaks the local git branch name into the "branch nick" field of commits, which could get pushed to a remote repository

Data leakage

  • Lots of different software leaks software names and version numbers into output

    • DNS servers respond with it to this command: dig +short @f.root-servers.net version.bind chaos txt

      • These DNS servers are definitely affected: unbound, bind

    • Mail user agents leak this into one of several headers: User-Agent Mailer X-Mailer

      • These MUAs are definitely affected: evolution

    • XMMP clients leak this in resource names or the Operating System and or Client fields of responses to "Get Info" requests

      • These clients are definitely affected: bitlbee libpurple conversations profanity psi

    • Mail servers leak this into the Received header

      • These MTAs are definitely affected: exim

    • Web browsers leak this into the User-Agent header

      • Almost all HTTP clients do this by default
    • File format writing software leaks this into files

      • Inkscape leaks this into the inkscape:version attribute of the svg element of SVG files.

  • Some software leaks the local time or timezone
    • Probably almost all protocols and clients do this

    • Web browsers leak this to the getTimezoneOffset() ?JavaScript

      • All modern web browsers do this, less modern ones may or may not

    • XMMP clients leak this in the Local Time field of responses to "Get Info" requests

      • These clients are definitely affected: bitlbee libpurple psi
  • Some software leaks local paths

    • Inkscape leaks the local path to the exported PNG file into the inkscape:export-filename attribute of the svg element of SVG files.

Data storage

  • web and other servers of various kinds default to logging information about requests over the network from external entities

Telemetry libraries

Debian contains some telemetry client libraries and some packages depend or build-depend on them. The code calling these libraries may or may not be active by default, often API keys are required before data may be submitted.

Logging

Servers listening on the network may log information about visitors to the service.

There are many kinds of servers that do this:

  • Web (listen on port 80/443):
    • apache2: logs client IP addresses by default, default retention period 2 weeks

See also