Security Working Group Minutes

Erlang Ecosystem Foundation EEF Security
6

May 29, 2024

Participants: @maennchen, @max-au, Paul Swartz, @ingela, @rickard, @voltone

Marvin attack and OTP 27 deprecations

  • Background: The Marvin Attack
  • OTP 27 deprecates asymmetrical encryption/decryption functions in crypto and public_key
    • RSA key exchange, which uses these functions, was already disabled by default due to the ROBOT attack; it is now actively discouraged
    • Fixing or deprecating these functions was pushed for by the researchers behind the Marvin attack
    • Practically not possible for OTP team to guarantee these functions are safe, as it depends on libcrypto dependency
  • No plans to remove these functions, likely to stick around for quite a while
    • At least until RSA key exchange, as a compatibility option, is completely removed
    • If/when there is a plan for removal, it will be announced well in advance
  • Could other use-cases, in 3rd party apps/libraries, be safe?
    • Depends on the threat model: can an attacker attempt many decryptions and measure the runtime?
    • What alternative do authors have? Adding custom libcrypto bindings adds complexity and could introduce new vulnerabilities
  • Plan: improve documentation, warn about risks, explain what plans OTP team have with these functions

Next meeting

Wed 26 June 2024 at 16:00 CEST / 14:00 GMT / 10am EDT / 7am PDT / 23:00 JST

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