librpcsecgss is an implementation of RPCSEC_GSS for secure RPC communications.
A stack based buffer overflow has been discovered in the svcauth_gss_validate() function in file lib/rpc/svc_auth_gss.c when processing an overly long string in a RPC message.
A remote attacker could send a specially crafted RPC request to an application relying on this library, e.g NFSv4 or Kerberos (GLSA-200709-01), resulting in the execution of arbitrary code with the privileges of the user running the application.
There is no known workaround at this time.
All librpcsecgss users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=net-libs/librpcsecgss-0.16"