mirror of
https://github.com/Ponce/slackbuilds
synced 2024-11-16 19:50:19 +01:00
85 lines
1.9 KiB
Diff
85 lines
1.9 KiB
Diff
Description: Fix symlink directory traversal.
|
|
Do not allow symlinks that traverse the current directoru, nor absolute
|
|
symlinks.
|
|
.
|
|
Fixes CVE-2015-0556.
|
|
Author: Guillem Jover <guillem@debian.org>
|
|
Origin: vendor
|
|
Bug-Debian: https://bugs.debian.org/774434
|
|
Forwarded: no
|
|
Last-Update: 2015-03-28
|
|
|
|
---
|
|
uxspec.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
|
|
1 file changed, 54 insertions(+)
|
|
|
|
--- a/uxspec.c
|
|
+++ b/uxspec.c
|
|
@@ -120,6 +120,58 @@ int query_uxspecial(char FAR **dest, cha
|
|
}
|
|
#endif
|
|
|
|
+#if TARGET==UNIX
|
|
+static int is_link_traversal(const char *name)
|
|
+{
|
|
+ enum {
|
|
+ STATE_NONE,
|
|
+ STATE_DOTS,
|
|
+ STATE_NAME,
|
|
+ } state = STATE_NONE;
|
|
+ int ndir = 0;
|
|
+ int dots = 0;
|
|
+
|
|
+ while(*name) {
|
|
+ int c = *name++;
|
|
+
|
|
+ if (c == '/')
|
|
+ {
|
|
+ if ((state == STATE_DOTS) && (dots == 2))
|
|
+ ndir--;
|
|
+ if (ndir < 0)
|
|
+ return 1;
|
|
+ if ((state == STATE_DOTS && dots == 1) && ndir == 0)
|
|
+ return 1;
|
|
+ if (state == STATE_NONE && ndir == 0)
|
|
+ return 1;
|
|
+ if ((state == STATE_DOTS) && (dots > 2))
|
|
+ ndir++;
|
|
+ state = STATE_NONE;
|
|
+ dots = 0;
|
|
+ }
|
|
+ else if (c == '.')
|
|
+ {
|
|
+ if (state == STATE_NONE)
|
|
+ state = STATE_DOTS;
|
|
+ dots++;
|
|
+ }
|
|
+ else
|
|
+ {
|
|
+ if (state == STATE_NONE)
|
|
+ ndir++;
|
|
+ state = STATE_NAME;
|
|
+ }
|
|
+ }
|
|
+
|
|
+ if ((state == STATE_DOTS) && (dots == 2))
|
|
+ ndir--;
|
|
+ if ((state == STATE_DOTS) && (dots > 2))
|
|
+ ndir++;
|
|
+
|
|
+ return ndir < 0;
|
|
+}
|
|
+#endif
|
|
+
|
|
/* Restores the UNIX special file data */
|
|
|
|
int set_uxspecial(char FAR *storage, char *name)
|
|
@@ -156,6 +208,8 @@ int set_uxspecial(char FAR *storage, cha
|
|
l=sizeof(tmp_name)-1;
|
|
far_memmove((char FAR *)tmp_name, dptr, l);
|
|
tmp_name[l]='\0';
|
|
+ if (is_link_traversal(tmp_name))
|
|
+ return(UXSPEC_RC_ERROR);
|
|
rc=(id==UXSB_HLNK)?link(tmp_name, name):symlink(tmp_name, name);
|
|
if(!rc)
|
|
return(0);
|