Yum

Installing software packages from untrusted third-party repositories poses substantial security risks. In RPM-based systems (RHEL, CentOS, Fedora), an RPM is not merely an archive of binaries—it contains cryptographic signatures, file digests, and embedded shell scripts (“scriptlets”) that execute with full root privileges during installation and removal. Here is how to audit RPM package integrity and inspect scriptlets prior to execution. 1. Auditing Installed GPG Keys When YUM/DNF installs signed packages, it checks them against GPG public keys registered in the local RPM database. ...

Default Red Hat Enterprise Linux (RHEL) and CentOS installations include only core system packages. To install modern software stacks, development tools, and updated dependencies, administrators frequently configure trusted third-party repositories. Here are the most common repositories and how to enable them on CentOS / RHEL: 1. EPEL (Extra Packages for Enterprise Linux) Maintained by the Fedora Special Interest Group, EPEL provides a massive collection of high-quality supplemental packages: sudo yum install epel-release -y 2. IUS (Inline with Upstream Stable) Provides up-to-date versions of key software (such as Python and Git) for Enterprise Linux: ...