Red Hat libsolv: denial of service

A flaw was found in libsolv, a dependency-resolution library used by RPM-based package managers such as dnf and zypper to work with .solv repository cache files. When libsolv rewrites a .solv cache file, it reads directory-id values from the file's compressed filelist data without validating that they fall within the expected range. A corrupted or specially crafted .solv cache file (for example, one left in a torn state after an unclean system shutdown) can cause an out-of-bounds memory write when a tool such as dnf, yum, or zypper next processes it. Successful exploitation is expected to result in a crash of the affected tool (denial of service); it is not expected to allow arbitrary code execution because the out-of-bounds write always stores a fixed, non-attacker-controlled value.