freebsd-ports/print/enscript-letter/files/patch-src_util.c
Christian Weisgerber 44a125dbb2 Security fixes:
Erik Sjolund discovered several issues in enscript: it suffers from
several buffer overflows (CAN-2004-1186), quotes and shell escape
characters are insufficiently sanitized in filenames (CAN-2004-1185),
and it supported taking input from an arbitrary command pipe, with
unwanted side effects (CAN-2004-1184).

Obtained from:	Gentoo
2005-02-11 21:35:40 +00:00

82 lines
1.7 KiB
C

$FreeBSD$
--- src/util.c.orig
+++ src/util.c
@@ -1239,6 +1239,8 @@
/* Create result. */
cp = xmalloc (len + 1);
+ if (cp == NULL)
+ return NULL;
for (i = 0, j = 0; string[i]; i++)
switch (string[i])
{
@@ -1879,6 +1881,7 @@
char *cmd = NULL;
int cmdlen;
int i, pos;
+ char *cp;
is->is_pipe = 1;
@@ -1902,12 +1905,16 @@
{
case 's':
/* Expand cmd-buffer. */
- cmdlen += strlen (fname);
- cmd = xrealloc (cmd, cmdlen);
+ if ((cp = shell_escape (fname)) != NULL)
+ {
+ cmdlen += strlen (cp);
+ cmd = xrealloc (cmd, cmdlen);
- /* Paste filename. */
- strcpy (cmd + pos, fname);
- pos += strlen (fname);
+ /* Paste filename. */
+ strcpy (cmd + pos, cp);
+ pos += strlen (cp);
+ free (cp);
+ }
i++;
break;
@@ -2115,4 +2122,37 @@
buffer_len (Buffer *buffer)
{
return buffer->len;
+}
+
+/*
+ * Escapes the name of a file so that the shell groks it in 'single'
+ * quotation marks. The resulting pointer has to be free()ed when not
+ * longer used.
+*/
+char *
+shell_escape(const char *fn)
+{
+ size_t len = 0;
+ const char *inp;
+ char *retval, *outp;
+
+ for(inp = fn; *inp; ++inp)
+ switch(*inp)
+ {
+ case '\'': len += 4; break;
+ default: len += 1; break;
+ }
+
+ outp = retval = malloc(len + 1);
+ if(!outp)
+ return NULL; /* perhaps one should do better error handling here */
+ for(inp = fn; *inp; ++inp)
+ switch(*inp)
+ {
+ case '\'': *outp++ = '\''; *outp++ = '\\'; *outp++ = '\'', *outp++ = '\''; break;
+ default: *outp++ = *inp; break;
+ }
+ *outp = 0;
+
+ return retval;
}