Ruby 1.9.3 before patchlevel 286 and 2.0 before revision r37068 allows
context-dependent attackers to bypass safe-level restrictions and modify
untainted strings via the (1) exc_to_s or (2) name_err_to_s API function,
which marks the string as tainted, a different vulnerability than
CVE-2012-4466. NOTE: this issue might exist because of a CVE-2011-1005
regression.