dpkg: Security Advisory - CVE-2014-0471

v2 changes:
* update format for commit log
* add Upstream-Status for patch

commit a82651188476841d190c58693f95827d61959b51 upstream

Dkpkg::Source::Patch: Correctly parse C-style diff filenames

We need to strip the surrounding quotes, and unescape any escape
sequence, so that we check the same files that the patch program will
be using, otherwise a malicious package could overpass those checks,
and perform directory traversal attacks on source package unpacking.

Fixes: CVE-2014-0471

Reported-by: Jakub Wilk <jwilk@debian.org>
[drop the text for debian/changelog,because it's not suitable
 for the veriosn]

(From OE-Core rev: 81880b34a8261e824c5acafaa4cb321908e554a0)

Signed-off-by: Wenlin Kang <wenlin.kang@windriver.com>
Signed-off-by: Wenzong Fan <wenzong.fan@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
This commit is contained in:
Guillem Jover
2014-06-17 04:25:51 -04:00
committed by Richard Purdie
parent c44d7b5cde
commit 4eea29a54a
2 changed files with 98 additions and 0 deletions

View File

@@ -0,0 +1,97 @@
dpkg: Security Advisory - CVE-2014-0471
commit a82651188476841d190c58693f95827d61959b51 upstream
Directory traversal vulnerability in the unpacking functionality in
dpkg before 1.15.9, 1.16.x before 1.16.13, and 1.17.x before 1.17.8
allows remote attackers to write arbitrary files via a crafted source
package, related to "C-style filename quoting."
Upstream-Status: Backport
Signed-off-by: Wenlin Kang <wenlin.kang@windriver.com>
Signed-off-by: Wenzong Fan <wenzong.fan@windriver.com>
===================================================
diff -uarN dpkg-1.17.1-org/scripts/Dpkg/Source/Patch.pm dpkg-1.17.1/scripts/Dpkg/Source/Patch.pm
--- dpkg-1.17.1-org/scripts/Dpkg/Source/Patch.pm 2014-06-05 15:24:07.422446284 +0800
+++ dpkg-1.17.1/scripts/Dpkg/Source/Patch.pm 2014-06-05 15:41:37.746446314 +0800
@@ -324,14 +324,53 @@
return $line;
}
-# Strip timestamp
-sub _strip_ts {
- my $header = shift;
-
- # Tab is the official separator, it's always used when
- # filename contain spaces. Try it first, otherwise strip on space
- # if there's no tab
- $header =~ s/\s.*// unless ($header =~ s/\t.*//);
+my %ESCAPE = ((
+ 'a' => "\a",
+ 'b' => "\b",
+ 'f' => "\f",
+ 'n' => "\n",
+ 'r' => "\r",
+ 't' => "\t",
+ 'v' => "\cK",
+ '\\' => '\\',
+ '"' => '"',
+), (
+ map { sprintf('%03o', $_) => chr($_) } (0..255)
+));
+
+sub _unescape {
+ my ($diff, $str) = @_;
+
+ if (exists $ESCAPE{$str}) {
+ return $ESCAPE{$str};
+ } else {
+ error(_g('diff %s patches file with unknown escape sequence \\%s'),
+ $diff, $str);
+ }
+}
+
+# Fetch the header filename ignoring the optional timestamp
+sub _fetch_filename {
+ my ($diff, $header) = @_;
+
+ # Strip any leading spaces.
+ $header =~ s/^\s+//;
+
+ # Is it a C-style string?
+ if ($header =~ m/^"/) {
+ $header =~ m/^"((?:[^\\"]|\\.)*)"/;
+ error(_g('diff %s patches file with unbalanced quote'), $diff)
+ unless defined $1;
+
+ $header = $1;
+ $header =~ s/\\([0-3][0-7]{2}|.)/_unescape($diff, $1)/eg;
+ } else {
+ # Tab is the official separator, it's always used when
+ # filename contain spaces. Try it first, otherwise strip on space
+ # if there's no tab
+ $header =~ s/\s.*// unless $header =~ s/\t.*//;
+ }
+
return $header;
}
@@ -400,7 +439,7 @@
unless(s/^--- //) {
error(_g("expected ^--- in line %d of diff `%s'"), $., $diff);
}
- $path{old} = $_ = _strip_ts($_);
+ $path{old} = $_ = _fetch_filename($diff, $_);
$fn{old} = $_ if $_ ne '/dev/null' and s{^[^/]*/+}{$destdir/};
if (/\.dpkg-orig$/) {
error(_g("diff `%s' patches file with name ending .dpkg-orig"), $diff);
@@ -412,7 +451,7 @@
unless (s/^\+\+\+ //) {
error(_g("line after --- isn't as expected in diff `%s' (line %d)"), $diff, $.);
}
- $path{new} = $_ = _strip_ts($_);
+ $path{new} = $_ = _fetch_filename($diff, $_);
$fn{new} = $_ if $_ ne '/dev/null' and s{^[^/]*/+}{$destdir/};
unless (defined $fn{old} or defined $fn{new}) {

View File

@@ -12,6 +12,7 @@ SRC_URI += "file://noman.patch \
file://dpkg-configure.service \
file://glibc2.5-sync_file_range.patch \
file://no-vla-warning.patch \
file://dpkg-1.17.4-CVE-2014-0471.patch \
"
SRC_URI[md5sum] = "cc25086e1e3bd9512a95f14cfe9002e1"