The wordexp function in GNU C Library (aka glibc) 2.21 does not enforce the WRDE_NOCMD flag, which allows context-dependent attackers to execute arbitrary commands, as demonstrated by input containing "$((...))".
Exploitability
AV:LAC:LAu:NImpact
C:PI:PA:P4.6/AV:L/AC:L/Au:N/C:P/I:P/A:P