Problems with creating hard links, buffer overflow, changing files ownership, etc.
vulners.com/securityvulns/securityvulns:doc:4841
vulners.com/securityvulns/securityvulns:doc:4842
vulners.com/securityvulns/securityvulns:doc:4843
vulners.com/securityvulns/securityvulns:doc:4844