webadmin/bpfire
1
0
Fork 0
mirror of https://github.com/vincentmli/bpfire.git synced 2026-04-09 18:45:54 +02:00
Code Issues Packages Projects Releases Wiki Activity

bash: Fix for CVE-2014-6271

Browse Source 
A flaw was found in the way Bash evaluated certain specially crafted
environment variables. An attacker could use this flaw to override
or bypass environment restrictions to execute shell commands.
Certain services and applications allow remote unauthenticated
attackers to provide environment variables, allowing them to exploit
this issue.
This commit is contained in:
Michael Tremer
2014-09-24 21:02:22 +02:00
parent 77192e97b9
commit 9445ab4acc
2 changed files with 92 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

1
lfs/bash
View File

@@ -94,6 +94,7 @@ $(TARGET) : $(patsubst %,$(DIR_DL)/%,$(objects))
cd $(DIR_APP) && patch -Np1 < $(DIR_SRC)/src/patches/bash-4.0-paths-1.patch
cd $(DIR_APP) && patch -Np1 < $(DIR_SRC)/src/patches/bash-4.0-profile-1.patch
cd $(DIR_APP) && patch -Np1 < $(DIR_SRC)/src/patches/bash-3.2-ssh_source_bash.patch
cd $(DIR_APP) && patch -Np0 < $(DIR_SRC)/src/patches/bash-4.3-CVE-2014-6271.patch
cd $(DIR_APP) && ./configure $(CONFIGURE_OPTIONS)
cd $(DIR_APP) && make $(MAKETUNING)

91
src/patches/bash-4.3-CVE-2014-6271.patch Normal file
View File

@@ -0,0 +1,91 @@
*** ../bash-4.3-patched/builtins/common.h 2013-07-08 16:54:47.000000000 -0400
--- builtins/common.h 2014-09-12 14:25:47.000000000 -0400
***************
*** 34,37 ****
--- 49,54 ----
#define SEVAL_PARSEONLY 0x020
#define SEVAL_NOLONGJMP 0x040
+ #define SEVAL_FUNCDEF 0x080 /* only allow function definitions */
+ #define SEVAL_ONECMD 0x100 /* only allow a single command */
/* Flags for describe_command, shared between type.def and command.def */
*** ../bash-4.3-patched/builtins/evalstring.c 2014-02-11 09:42:10.000000000 -0500
--- builtins/evalstring.c 2014-09-14 14:15:13.000000000 -0400
***************
*** 309,312 ****
--- 313,324 ----
struct fd_bitmap *bitmap;
+ if ((flags & SEVAL_FUNCDEF) && command->type != cm_function_def)
+ {
+ internal_warning ("%s: ignoring function definition attempt", from_file);
+ should_jump_to_top_level = 0;
+ last_result = last_command_exit_value = EX_BADUSAGE;
+ break;
+ }
+
bitmap = new_fd_bitmap (FD_BITMAP_SIZE);
begin_unwind_frame ("pe_dispose");
***************
*** 369,372 ****
--- 381,387 ----
dispose_fd_bitmap (bitmap);
discard_unwind_frame ("pe_dispose");
+
+ if (flags & SEVAL_ONECMD)
+ break;
}
}
*** ../bash-4.3-patched/variables.c 2014-05-15 08:26:50.000000000 -0400
--- variables.c 2014-09-14 14:23:35.000000000 -0400
***************
*** 359,369 ****
strcpy (temp_string + char_index + 1, string);
! if (posixly_correct == 0 || legal_identifier (name))
! parse_and_execute (temp_string, name, SEVAL_NONINT|SEVAL_NOHIST);
!
! /* Ancient backwards compatibility. Old versions of bash exported
! functions like name()=() {...} */
! if (name[char_index - 1] == ')' && name[char_index - 2] == '(')
! name[char_index - 2] = '\0';
if (temp_var = find_function (name))
--- 364,372 ----
strcpy (temp_string + char_index + 1, string);
! /* Don't import function names that are invalid identifiers from the
! environment, though we still allow them to be defined as shell
! variables. */
! if (legal_identifier (name))
! parse_and_execute (temp_string, name, SEVAL_NONINT|SEVAL_NOHIST|SEVAL_FUNCDEF|SEVAL_ONECMD);
if (temp_var = find_function (name))
***************
*** 382,389 ****
report_error (_("error importing function definition for `%s'"), name);
}
-
- /* ( */
- if (name[char_index - 1] == ')' && name[char_index - 2] == '\0')
- name[char_index - 2] = '('; /* ) */
}
#if defined (ARRAY_VARS)
--- 385,388 ----
*** ../bash-4.3-patched/subst.c 2014-08-11 11:16:35.000000000 -0400
--- subst.c 2014-09-12 15:31:04.000000000 -0400
***************
*** 8048,8052 ****
goto return0;
}
! else if (var = find_variable_last_nameref (temp1))
{
temp = nameref_cell (var);
--- 8118,8124 ----
goto return0;
}
! else if (var && (invisible_p (var) || var_isset (var) == 0))
! temp = (char *)NULL;
! else if ((var = find_variable_last_nameref (temp1)) && var_isset (var) && invisible_p (var) == 0)
{
temp = nameref_cell (var);