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BASH PATCH REPORT
=================
Bash-Release: 4.3
Patch-ID: bash43-048
Bug-Reported-by: up201407890@alunos.dcc.fc.up.pt
Bug-Reference-ID: <20151210201649.126444eionzfsam8@webmail.alunos.dcc.fc.up.pt>
Bug-Reference-URL: http://lists.gnu.org/archive/html/bug-bash/2015-12/msg00054.html
Bug-Description:
If a malicious user can inject a value of $SHELLOPTS containing `xtrace'
and a value for $PS4 that includes a command substitution into a shell
running as root, bash will expand the command substitution as part of
expanding $PS4 when it executes a traced command.
Patch (apply with `patch -p0'):
--- a/variables.c
+++ b/variables.c
@@ -495,7 +495,11 @@ initialize_shell_variables (env, privmod
#endif
set_if_not ("PS2", secondary_prompt);
}
- set_if_not ("PS4", "+ ");
+
+ if (current_user.euid == 0)
+ bind_variable ("PS4", "+ ", 0);
+ else
+ set_if_not ("PS4", "+ ");
/* Don't allow IFS to be imported from the environment. */
temp_var = bind_variable ("IFS", " \t\n", 0);
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