Pluggable Authentication Modules (PAM) provide a system wherebyadministrators can set up authentication policies without having torecompile programs that handle authentication.It was discovered that the pam_namespace module executed the externalscript namespace.init with an unchanged environment inherited from anapplication calling PAM. In cases where such an environment was untrusted(for example, when pam_namespace was configured for setuid applicationssuch as su or sudo), a local, unprivileged user could possibly use thisflaw to escalate their privileges. (CVE-2010-3853)It was discovered that the pam_mail module used root privileges whileaccessing users' files. In certain configurations, a local, unprivilegeduser could use this flaw to obtain limited information about files ordirectories that they do not have access to. (CVE-2010-3435)It was discovered that the pam_xauth module did not verify the returnvalues of the setuid() and setgid() system calls. A local, unprivilegeduser could use this flaw to execute the xauth command with root privilegesand make it read an arbitrary input file. (CVE-2010-3316)Red Hat would like to thank Sebastian Krahmer of the SuSE Security Team forreporting the CVE-2010-3435 issue.All pam users should upgrade to these updated packages, which containbackported patches to correct these issues.