ID CVE-2016-6321
Summary Directory traversal vulnerability in the safer_name_suffix function in GNU tar 1.14 through 1.29 might allow remote attackers to bypass an intended protection mechanism and write to arbitrary files via vectors related to improper sanitization of the file_name parameter, aka POINTYFEATHER.
References
Vulnerable Configurations
  • GNU Tar 1.24
    cpe:2.3:a:gnu:tar:1.24
  • GNU Tar 1.25
    cpe:2.3:a:gnu:tar:1.25
  • GNU Tar 1.26
    cpe:2.3:a:gnu:tar:1.26
  • GNU Tar 1.27
    cpe:2.3:a:gnu:tar:1.27
  • GNU Tar 1.27.1
    cpe:2.3:a:gnu:tar:1.27.1
  • GNU Tar 1.28
    cpe:2.3:a:gnu:tar:1.28
  • GNU Tar 1.29
    cpe:2.3:a:gnu:tar:1.29
  • GNU tar 1.14
    cpe:2.3:a:gnu:tar:1.14
  • GNU tar 1.15
    cpe:2.3:a:gnu:tar:1.15
  • GNU tar 1.15.1
    cpe:2.3:a:gnu:tar:1.15.1
  • GNU tar 1.15.90
    cpe:2.3:a:gnu:tar:1.15.90
  • GNU tar 1.15.91
    cpe:2.3:a:gnu:tar:1.15.91
  • GNU tar 1.16
    cpe:2.3:a:gnu:tar:1.16
  • GNU Tar 1.16.1
    cpe:2.3:a:gnu:tar:1.16.1
  • GNU Tar 1.17
    cpe:2.3:a:gnu:tar:1.17
  • GNU Tar 1.18
    cpe:2.3:a:gnu:tar:1.18
  • GNU Tar 1.19
    cpe:2.3:a:gnu:tar:1.19
  • GNU Tar 1.20
    cpe:2.3:a:gnu:tar:1.20
  • GNU Tar 1.21
    cpe:2.3:a:gnu:tar:1.21
  • GNU Tar 1.22
    cpe:2.3:a:gnu:tar:1.22
  • GNU Tar 1.23
    cpe:2.3:a:gnu:tar:1.23
CVSS
Base: 5.0 (as of 13-12-2016 - 14:10)
Impact:
Exploitability:
CWE CWE-22
CAPEC
  • Relative Path Traversal
    An attacker exploits a weakness in input validation on the target by supplying a specially constructed path utilizing dot and slash characters for the purpose of obtaining access to arbitrary files or resources. An attacker modifies a known path on the target in order to reach material that is not available through intended channels. These attacks normally involve adding additional path separators (/ or \) and/or dots (.), or encodings thereof, in various combinations in order to reach parent directories or entirely separate trees of the target's directory structure.
  • Directory Traversal
    An attacker with access to file system resources, either directly or via application logic, will use various file path specification or navigation mechanisms such as ".." in path strings and absolute paths to extend their range of access to inappropriate areas of the file system. The attacker attempts to either explore the file system for recon purposes or access directories and files that are intended to be restricted from their access. Exploring the file system can be achieved through constructing paths presented to directory listing programs, such as "ls" and 'dir', or through specially crafted programs that attempt to explore the file system. The attacker engaging in this type of activity is searching for information that can be used later in a more exploitive attack. Access to restricted directories or files can be achieved through modification of path references utilized by system applications.
  • File System Function Injection, Content Based
    An attack of this type exploits the host's trust in executing remote content including binary files. The files are poisoned with a malicious payload (targeting the file systems accessible by the target software) by the attacker and may be passed through standard channels such as via email, and standard web content like PDF and multimedia files. The attacker exploits known vulnerabilities or handling routines in the target processes. Vulnerabilities of this type have been found in a wide variety of commercial applications from Microsoft Office to Adobe Acrobat and Apple Safari web browser. When the attacker knows the standard handling routines and can identify vulnerabilities and entry points they can be exploited by otherwise seemingly normal content. Once the attack is executed, the attackers' program can access relative directories such as C:\Program Files or other standard system directories to launch further attacks. In a worst case scenario, these programs are combined with other propagation logic and work as a virus.
  • Using Slashes and URL Encoding Combined to Bypass Validation Logic
    This attack targets the encoding of the URL combined with the encoding of the slash characters. An attacker can take advantage of the multiple way of encoding an URL and abuse the interpretation of the URL. An URL may contain special character that need special syntax handling in order to be interpreted. Special characters are represented using a percentage character followed by two digits representing the octet code of the original character (%HEX-CODE). For instance US-ASCII space character would be represented with %20. This is often referred as escaped ending or percent-encoding. Since the server decodes the URL from the requests, it may restrict the access to some URL paths by validating and filtering out the URL requests it received. An attacker will try to craft an URL with a sequence of special characters which once interpreted by the server will be equivalent to a forbidden URL. It can be difficult to protect against this attack since the URL can contain other format of encoding such as UTF-8 encoding, Unicode-encoding, etc.
  • Manipulating Input to File System Calls
    An attacker manipulates inputs to the target software which the target software passes to file system calls in the OS. The goal is to gain access to, and perhaps modify, areas of the file system that the target software did not intend to be accessible.
  • Using Escaped Slashes in Alternate Encoding
    This attack targets the use of the backslash in alternate encoding. An attacker can provide a backslash as a leading character and causes a parser to believe that the next character is special. This is called an escape. By using that trick, the attacker tries to exploit alternate ways to encode the same character which leads to filter problems and opens avenues to attack.
  • Using Slashes in Alternate Encoding
    This attack targets the encoding of the Slash characters. An attacker would try to exploit common filtering problems related to the use of the slashes characters to gain access to resources on the target host. Directory-driven systems, such as file systems and databases, typically use the slash character to indicate traversal between directories or other container components. For murky historical reasons, PCs (and, as a result, Microsoft OSs) choose to use a backslash, whereas the UNIX world typically makes use of the forward slash. The schizophrenic result is that many MS-based systems are required to understand both forms of the slash. This gives the attacker many opportunities to discover and abuse a number of common filtering problems. The goal of this pattern is to discover server software that only applies filters to one version, but not the other.
Access
VectorComplexityAuthentication
NETWORK LOW NONE
Impact
ConfidentialityIntegrityAvailability
NONE PARTIAL NONE
nessus via4
  • NASL family SuSE Local Security Checks
    NASL id SUSE_SU-2016-2896-1.NASL
    description This update for tar fixes the following issues : - Fix the POINTYFEATHER vulnerability - GNU tar archiver can be tricked into extracting files and directories in the given destination, regardless of the path name(s) specified on the command line [bsc#1007188] [CVE-2016-6321] - Fix Amanda integration issue (bsc#913058) Note that Tenable Network Security has extracted the preceding description block directly from the SUSE security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
    last seen 2019-02-21
    modified 2018-11-29
    plugin id 95315
    published 2016-11-25
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=95315
    title SUSE SLED12 / SLES12 Security Update : tar (SUSE-SU-2016:2896-1)
  • NASL family SuSE Local Security Checks
    NASL id OPENSUSE-2016-1341.NASL
    description This update for tar fixes the following issues : - extract files recursively with --files-from [boo#913058] - Fix POINTYFEATHER vulnerability - GNU tar archiver can be tricked into extracting files and directories in the given destination, regardless of the path name(s) specified on the command line [boo#1007188] [CVE-2016-6321]
    last seen 2019-02-21
    modified 2016-12-21
    plugin id 95273
    published 2016-11-23
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=95273
    title openSUSE Security Update : tar (openSUSE-2016-1341)
  • NASL family SuSE Local Security Checks
    NASL id OPENSUSE-2016-1401.NASL
    description This update for tar fixes the following issues : - Fix the POINTYFEATHER vulnerability - GNU tar archiver can be tricked into extracting files and directories in the given destination, regardless of the path name(s) specified on the command line [bsc#1007188] [CVE-2016-6321] - Fix Amanda integration issue (bsc#913058) This update was imported from the SUSE:SLE-12:Update update project.
    last seen 2019-02-21
    modified 2016-12-21
    plugin id 95555
    published 2016-12-06
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=95555
    title openSUSE Security Update : tar (openSUSE-2016-1401)
  • NASL family SuSE Local Security Checks
    NASL id SUSE_SU-2016-2895-1.NASL
    description This update for tar fixes the following issues : - Fix the POINTYFEATHER vulnerability - GNU tar archiver can be tricked into extracting files and directories in the given destination, regardless of the path name(s) specified on the command line [bsc#1007188] [CVE-2016-6321] Note that Tenable Network Security has extracted the preceding description block directly from the SUSE security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
    last seen 2019-02-21
    modified 2018-11-29
    plugin id 95314
    published 2016-11-25
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=95314
    title SUSE SLES11 Security Update : tar (SUSE-SU-2016:2895-1)
  • NASL family Ubuntu Local Security Checks
    NASL id UBUNTU_USN-3132-1.NASL
    description Harry Sintonen discovered that tar incorrectly handled extracting files when path names are specified on the command line. If a user or automated system were tricked into processing a specially crafted archive, an attacker could possibly overwrite arbitrary files. Note that Tenable Network Security has extracted the preceding description block directly from the Ubuntu security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
    last seen 2019-02-21
    modified 2018-12-01
    plugin id 95054
    published 2016-11-22
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=95054
    title Ubuntu 12.04 LTS / 14.04 LTS / 16.04 LTS / 16.10 : tar vulnerability (USN-3132-1)
  • NASL family Debian Local Security Checks
    NASL id DEBIAN_DLA-690.NASL
    description A vulnerability has been discovered in the tar package that could allow an attacker to overwrite arbitrary files through crafted files. For Debian 7 'Wheezy', these problems have been fixed in version 1.26+dfsg-0.1+deb7u1. We recommend that you upgrade your tar packages. NOTE: Tenable Network Security has extracted the preceding description block directly from the DLA security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
    last seen 2019-02-21
    modified 2018-07-10
    plugin id 94447
    published 2016-11-01
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=94447
    title Debian DLA-690-1 : tar security update
  • NASL family Gentoo Local Security Checks
    NASL id GENTOO_GLSA-201611-19.NASL
    description The remote host is affected by the vulnerability described in GLSA-201611-19 (Tar: Extract pathname bypass) Tar attempts to avoid path traversal attacks by removing offending parts of the element name at extract. This sanitizing leads to a vulnerability where the attacker can bypass the path name(s) specified on the command line. Impact : The attacker can create a crafted tar archive that, if extracted by the victim, replaces files and directories the victim has access to in the target directory, regardless of the path name(s) specified on the command line. Workaround : There is no known workaround at this time.
    last seen 2019-02-21
    modified 2016-12-21
    plugin id 95270
    published 2016-11-23
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=95270
    title GLSA-201611-19 : Tar: Extract pathname bypass
  • NASL family Debian Local Security Checks
    NASL id DEBIAN_DSA-3702.NASL
    description Harry Sintonen discovered that GNU tar does not properly handle member names containing '..', thus allowing an attacker to bypass the path names specified on the command line and replace files and directories in the target directory.
    last seen 2019-02-21
    modified 2018-11-10
    plugin id 94456
    published 2016-11-02
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=94456
    title Debian DSA-3702-1 : tar - security update
  • NASL family PhotonOS Local Security Checks
    NASL id PHOTONOS_PHSA-2017-0015_TAR.NASL
    description An update of the tar package has been released.
    last seen 2019-02-08
    modified 2019-02-07
    plugin id 121690
    published 2019-02-07
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=121690
    title Photon OS 1.0: Tar PHSA-2017-0015
  • NASL family PhotonOS Local Security Checks
    NASL id PHOTONOS_PHSA-2017-0015.NASL
    description An update of [freetype2,tar,gnutls,linux] packages for PhotonOS has been released.
    last seen 2019-02-21
    modified 2019-02-07
    plugin id 111864
    published 2018-08-17
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=111864
    title Photon OS 1.0: Freetype2 / Gnutls / Linux / Tar PHSA-2017-0015 (deprecated)
packetstorm via4
data source https://packetstormsecurity.com/files/download/139370/tar-bypass.txt
id PACKETSTORM:139370
last seen 2016-12-05
published 2016-10-27
reporter Harry Sintonen
source https://packetstormsecurity.com/files/139370/GNU-tar-1.29-Extract-Pathname-Bypass.html
title GNU tar 1.29 Extract Pathname Bypass
refmap via4
bid 93937
confirm http://git.savannah.gnu.org/cgit/tar.git/commit/?id=7340f67b9860ea0531c1450e5aa261c50f67165d
debian DSA-3702
fulldisc
  • 20161026 [CSS] POINTYFEATHER / tar extract pathname bypass (CVE-2016-6321)
  • 20161030 [CSS] POINTYFEATHER / tar extract pathname bypass (CVE-2016-6321) - patch update
gentoo GLSA-201611-19
misc
mlist [bug-tar] 20161029 Re: [Bug-tar] possible fixes for CVE-2016-6321
ubuntu USN-3132-1
Last major update 06-01-2017 - 22:00
Published 09-12-2016 - 17:59
Last modified 30-06-2017 - 21:30
Back to Top