CVE-2016-7166 (published 2016-09-21T14:25Z)

libarchive before 3.2.0 does not limit the number of recursive decompressions, which allows remote attackers to cause a denial of service (memory consumption and application crash) via a crafted gzip file.

Severity: MEDIUM
CVSS v2 base score: 4.3 (AV:N/AC:M/Au:N/C:N/I:N/A:P)
CVSS v3 base score: 5.5, MEDIUM (CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H)

Weakness information:
cwe_id: CWE-399
cwe_name: Resource Management Errors
description: Weaknesses in this category are related to improper management of system resources.

Fix information:
repo_url: https://github.com/libarchive/libarchive
commit_details: repo_url: https://github.com/libarchive/libarchive
author: Tim Kientzle
author_date: 2015-01-10 12:24:58-08:00
msg: Fix a potential crash issue discovered by Alexander Cherepanov:

It seems bsdtar automatically handles stacked compression. This is a
nice feature but it could be problematic when it's completely
unlimited.  Most clearly it's illustrated with quines:

$ curl -sRO http://www.maximumcompression.com/selfgz.gz
$ (ulimit -v 10000000 && bsdtar -tvf selfgz.gz)
bsdtar: Error opening archive: Can't allocate data for gzip decompression

Without ulimit, bsdtar will eat all available memory. This could also
be a problem for other applications using libarchive.
repository: repo_url: https://github.com/libarchive/libarchive
repo_name: libarchive/libarchive
description: Multi-format archive and compression library
repo_language: C
owner: libarchive
file_changes: filename: Makefile.am
change_type: ModificationType.MODIFY
diff: @@ -482,6 +482,7 @@ libarchive_test_SOURCES= \
 	libarchive/test/test_read_pax_truncated.c \
 	libarchive/test/test_read_position.c \
 	libarchive/test/test_read_set_format.c \
+	libarchive/test/test_read_too_many_filters.c \
 	libarchive/test/test_read_truncated.c \
 	libarchive/test/test_read_truncated_filter.c \
 	libarchive/test/test_sparse_basic.c \
@@ -791,6 +792,7 @@ libarchive_test_EXTRA_DIST=\
 	libarchive/test/test_read_splitted_rar_ab.uu \
 	libarchive/test/test_read_splitted_rar_ac.uu \
 	libarchive/test/test_read_splitted_rar_ad.uu \
+	libarchive/test/test_read_too_many_filters.gz.uu \
 	libarchive/test/test_splitted_rar_seek_support_aa.uu \
 	libarchive/test/test_splitted_rar_seek_support_ab.uu \
 	libarchive/test/test_splitted_rar_seek_support_ac.uu \

programming_language: Shell
filename: archive_read.c
change_type: ModificationType.MODIFY
diff: @@ -548,13 +548,13 @@ archive_read_open1(struct archive *_a)
 static int
 choose_filters(struct archive_read *a)
 {
-	int number_bidders, i, bid, best_bid;
+	int number_bidders, i, bid, best_bid, n;
 	struct archive_read_filter_bidder *bidder, *best_bidder;
 	struct archive_read_filter *filter;
 	ssize_t avail;
 	int r;
 
-	for (;;) {
+	for (n = 0; n < 25; ++n) {
 		number_bidders = sizeof(a->bidders) / sizeof(a->bidders[0]);
 
 		best_bid = 0;
@@ -600,6 +600,9 @@ choose_filters(struct archive_read *a)
 			return (ARCHIVE_FATAL);
 		}
 	}
+	archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
+	    "Input requires too many filters for decoding");
+	return (ARCHIVE_FATAL);
 }
 
 /*

programming_language: C
filename: CMakeLists.txt
change_type: ModificationType.MODIFY
diff: @@ -172,6 +172,7 @@ IF(ENABLE_TEST)
     test_read_pax_truncated.c
     test_read_position.c
     test_read_set_format.c
+    test_read_too_many_filters.c
     test_read_truncated.c
     test_read_truncated_filter.c
     test_sparse_basic.c

programming_language: Shell
filename: test_read_too_many_filters.c
change_type: ModificationType.ADD
diff: @@ -0,0 +1,45 @@
+/*-
+ * Copyright (c) 2003-2008,2015 Tim Kientzle
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#include "test.h"
+
+DEFINE_TEST(test_read_too_many_filters)
+{
+	const char *name = "test_read_too_many_filters.gz";
+	struct archive *a;
+	int r;
+
+	assert((a = archive_read_new()) != NULL);
+	r = archive_read_support_filter_gzip(a);
+	if (r == ARCHIVE_WARN) {
+		skipping("gzip reading not fully supported on this platform");
+	}
+	assertEqualIntA(a, ARCHIVE_OK, archive_read_support_format_all(a));
+	extract_reference_file(name);
+	assertEqualIntA(a, ARCHIVE_FATAL,
+	    archive_read_open_filename(a, name, 200));
+
+	assertEqualInt(ARCHIVE_OK, archive_read_close(a));
+	assertEqualInt(ARCHIVE_OK, archive_read_free(a));
+}

programming_language: C
filename: test_read_too_many_filters.gz.uu
change_type: ModificationType.ADD
diff: @@ -0,0 +1,15 @@
+This is a valid gzip file that decompresses to itself, from
+  http://www.maximumcompression.com/selfgz.gz
+
+This is used in test_read_too_many_filters to try to
+crash libarchive by forcing it to spawn an unending
+list of gunzip filters.
+
+begin 644 test_read_too_many_filters.gz
+M'XL(`````````P`/`/#_'XL(`````````P`/`/#_````__\```#__X)QH5P`
+M`!X`X?\```#__P```/__@G&A7```'@#A_P```/__````__\```#__P```/__
+M````__\```#__\(FAF`!`!0`Z_\```#__P```/__PB:&8`$`%`#K_\(FAF`!
+M`!0`Z_^9(#6-B"@Q,C,T`K/`+```%`#K_P*SP"P``!0`Z_]"B"'$`````/__
+>`P!#2DTAT@```$*((<0`````__\#`$-*32'2````
+`
+end

programming_language: Markdown