Arch Linux Security Advisory ASA-201801-21
==========================================

Severity: High
Date    : 2018-01-29
CVE-ID  : CVE-2017-16548 CVE-2017-17433 CVE-2017-17434 CVE-2018-5764
Package : rsync
Type    : multiple issues
Remote  : Yes
Link    : https://security.archlinux.org/AVG-542

Summary
=======

The package rsync before version 3.1.3pre1-1 is vulnerable to multiple
issues including access restriction bypass and denial of service.

Resolution
==========

Upgrade to 3.1.3pre1-1.

# pacman -Syu "rsync>=3.1.3pre1-1"

The problems have been fixed upstream in version 3.1.3pre1.

Workaround
==========

None.

Description
===========

- CVE-2017-16548 (denial of service)

The receive_xattr function in xattrs.c in rsync 3.1.2 and
3.1.3-development does not check for a trailing '\0' character in an
xattr name, which allows remote attackers to cause a denial of service
(heap-based buffer over-read and application crash) or possibly have
unspecified other impact by sending crafted data to the daemon.

- CVE-2017-17433 (access restriction bypass)

The recv_files function in receiver.c in the daemon in rsync 3.1.2, and
3.1.3-development before 2017-11-03, proceeds with certain file
metadata updates before checking for a filename in the
daemon_filter_list data structure, which allows remote attackers to
bypass intended access restrictions.

- CVE-2017-17434 (access restriction bypass)

The daemon in rsync 3.1.2, and 3.1.3-development before 2017-12-03,
does not check for fnamecmp filenames in the daemon_filter_list data
structure (in the recv_files function in receiver.c) and also does not
apply the sanitize_paths protection mechanism to pathnames found in
"xname follows" strings (in the read_ndx_and_attrs function in
rsync.c), which allows remote attackers to bypass intended access
restrictions.

- CVE-2018-5764 (access restriction bypass)

The parse_arguments function in options.c in rsyncd in rsync before
3.1.3 does not prevent multiple --protect-args uses, which allows
remote attackers to bypass an argument-sanitization protection
mechanism.

Impact
======

A remote attacker is able to bypass access restrictions or cause a
denial of service by sending a maliciously crafted request to rsyncd.

References
==========

https://bugs.archlinux.org/task/57111
https://git.samba.org/?p=rsync.git;a=commitdiff;h=47a63d90e71d3e19e0e96052bb8c6b9cb140ecc1
https://git.samba.org/?p=rsync.git;a=commitdiff;h=3e06d40029cfdce9d0f73d87cfd4edaf54be9c51
https://git.samba.org/?p=rsync.git;a=commitdiff;h=5509597decdbd7b91994210f700329d8a35e70a1
https://git.samba.org/?p=rsync.git;a=commitdiff;h=70aeb5fddd1b2f8e143276f8d5a085db16c593b9
https://git.samba.org/?p=rsync.git;a=commitdiff;h=7706303828fcde524222babb2833864a4bd09e07
https://security.archlinux.org/CVE-2017-16548
https://security.archlinux.org/CVE-2017-17433
https://security.archlinux.org/CVE-2017-17434
https://security.archlinux.org/CVE-2018-5764