alpine 3.6
shell weakness #87


Weakness Breakdown


A shell weakness occurs when a program enables an attacker to execute unexpected commands on the operating system.

Warning code(s):

This causes a new program to execute and is difficult to use safely.

File Name:



The highlighted line of code below is the trigger point of this particular Alpine 3.6 shell weakness.

 #if defined(LUA_USE_MKSTEMP)
#include <unistd.h>
#define lua_tmpnam(b,e)	{ \
	strcpy(b, "/tmp/lua_XXXXXX"); \
	e = mkstemp(b); \
	if (e != -1) close(e); \
	e = (e == -1); }

#define LUA_TMPNAMBUFSIZE	L_tmpnam
#define lua_tmpnam(b,e)		{ e = (tmpnam(b) == NULL); }


@@ lua_popen spawns a new process connected to the current one through
@* the file streams.
** CHANGE it if you have a way to implement it in your system.
#if defined(LUA_USE_POPEN)

#define lua_popen(L,c,m)	((void)L, fflush(NULL), popen(c,m))
#define lua_pclose(L,file)	((void)L, (pclose(file) != -1))

#elif defined(LUA_WIN)

#define lua_popen(L,c,m)	((void)L, _popen(c,m))
#define lua_pclose(L,file)	((void)L, (_pclose(file) != -1))


#define lua_popen(L,c,m)	((void)((void)c, m),  \
		luaL_error(L, LUA_QL("popen") " not supported"), (FILE*)0)
#define lua_pclose(L,file)		((void)((void)L, file), 0)


@@ LUA_DL_* define which dynamic-library system Lua should use.
** CHANGE here if Lua has problems choosing the appropriate
** dynamic-library system for your platform (either Windows' DLL, Mac's
** dyld, or Unix's dlopen). If your system is some kind of Unix, there
** is a good chance that it has dlopen, so LUA_DL_DLOPEN will work for
** it.  To use dlopen you also need to adapt the src/Makefile (probably
** adding -ldl to the linker options), so Lua does not select it
** automatically.  (When you change the makefile to add -ldl, you must
** also add -DLUA_USE_DLOPEN.) 

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