Threats affecting pkg:deb/debian/dpkg

It was discovered that dpkg-deb (a component of dpkg, the Debian package management system) does not properly validate the end of the data stream when uncompressing a zstd-compressed .deb archive, which may result in denial of service (infinite loop spinning the CPU).

It was discovered that dpkg-deb does not properly sanitize directory permissions when extracting a control member into a temporary directory, which is documented as being a safe operation even on untrusted data. This may result in leaving temporary files behind on cleanup. Given automated and repeated execution of dpkg-deb commands on adversarial .deb packages or with well compressible files, placed inside a directory with permissions not allowing removal by a non-root user, this can end up in a DoS scenario due to causing disk quota exhaustion or disk full conditions.