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brianmario / yajl-ruby

A streaming JSON parsing and encoding library for Ruby (C bindings to yajl)
http://rdoc.info/projects/brianmario/yajl-ruby
MIT License
1.48k stars 169 forks source link

Version 1.4.2 #211

Closed jhawthorn closed 2 years ago

jhawthorn commented 2 years ago

Includes fix for CVE-2022-24795

Description

The 1.x branch and the 2.x branch of yajl contain an integer overflow which leads to subsequent heap memory corruption when dealing with large (~2GB) inputs.

Details

The reallocation logic at yajl_buf.c#L64 may result in the need 32bit integer wrapping to 0 when need approaches a value of 0x80000000 (i.e. ~2GB of data), which results in a reallocation of buf->alloc into a small heap chunk.

These integers are declared as size_t in the 2.x branch of yajl, which practically prevents the issue from triggering on 64bit platforms, however this does not preclude this issue triggering on 32bit builds on which size_t is a 32bit integer.

Subsequent population of this under-allocated heap chunk is based on the original buffer size, leading to heap memory corruption.

Impact

We rate this as a moderate severity vulnerability which mostly impacts process availability as we believe exploitation for arbitrary code execution to be unlikely.

Patches

Patched in yajl-ruby 1.4.2

Workarounds

Avoid passing large inputs to YAJL

References

https://github.com/brianmario/yajl-ruby/blob/7168bd79b888900aa94523301126f968a93eb3a6/ext/yajl/yajl_buf.c#L64

For more information

If you have any questions or comments about this advisory:

stevo-f3 commented 2 years ago

@jhawthorn it seems 1.4.2 changed required ruby version to >= 2.6.0 https://rubygems.org/gems/yajl-ruby/versions/1.4.2

yajl-ruby v1.4.1 required ruby >= 1.8.6 https://rubygems.org/gems/yajl-ruby/versions/1.4.1

This change breaks other gems like fluentd https://rubygems.org/gems/fluentd/versions/1.14.6 which have runtime dependency on yajl-ruby ~> 1.0 and claim to require ruby >= 2.4, but now they actually also require >= 2.6.0

Ubuntu 18.04 LTS has only v2.5.1 of ruby https://packages.ubuntu.com/search?keywords=ruby

Updating OS is non-trivial, requires more time. Before attempting to pin fluentd to use yajl-ruby v1.4.1, can you please share was the change to require ruby >= 2.6.0 in a yajl-ruby v1.4.2 patch release intentional?

drbugfinder-work commented 2 years ago

Looks like this fixes https://github.com/brianmario/yajl-ruby/issues/205

jhawthorn commented 2 years ago

@stevo-f3 I can appreciate the difficulty 😞, but Ruby 2.5 has been EOL for over a year, support was removed in a previous PR.