Headline
CVE-2022-39224: Only attempt extraction if a known payload compressor is used. by jordansissel · Pull Request #15 · jordansissel/ruby-arr-pm
Arr-pm is an RPM reader/writer library written in Ruby. Versions prior to 0.0.12 are subject to OS command injection resulting in shell execution if the RPM contains a malicious “payload compressor” field. This vulnerability impacts the extract and files methods of the RPM::File class of this library. Version 0.0.12 patches these issues. A workaround for this issue is to ensure any RPMs being processed contain valid/known payload compressor values such as gzip, bzip2, xz, zstd, and lzma. The payload compressor field in an rpm can be checked by using the rpm command line tool.
% bundle exec rspec spec/rpm/file_spec.rb -e compressor -f d
Run options: include {:full_description=>/compressor/}
RPM::File
#extract
with an invalid payloadcompressor
should raise an error
with a 'gzip' payloadcompressor
should succeed
with a 'bzip2' payloadcompressor
bzip2: (stdin) is not a bzip2 file.
cpio: premature end of archive
should succeed
with a 'xz' payloadcompressor
xz: (stdin): File format not recognized
cpio: premature end of archive
should succeed
with a 'lzma' payloadcompressor
lzma: (stdin): File format not recognized
cpio: premature end of archive
should succeed
with a 'zstd' payloadcompressor
should succeed
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6 examples, 0 failuresRelated news
### Impact Arbitrary shell execution is possible when using RPM::File#files and RPM::File#extract if the RPM contains a malicious "payload compressor" field. This vulnerability impacts the `extract` and `files` methods of the `RPM::File` class in the affected versions of this library. ### Patches Version 0.0.12 is available with a fix for these issues. ### Workarounds When using an affected version of this library (arr-pm), ensure any RPMs being processed contain valid/known payload compressor values. Such values include: gzip, bzip2, xz, zstd, and lzma. You can check the payload compressor field in an rpm by using the rpm command line tool. For example: ``` % rpm -qp example-1.0-1.x86_64.rpm --qf "%{PAYLOADCOMPRESSOR}\n" gzip ``` ### Impact on known dependent projects This library is used by [fpm](https://github.com/jordansissel/fpm). The vulnerability may impact fpm only when using the flag `-s rpm` or `--input-type rpm` to convert a malicious rpm to another format. It does...