VDB-93116 · CVE-2016-6321 · Nessus 95270

GNU tar up to 1.29 Extraction Path path traversal ⚔ [Disputed]

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
7.1	$0-$5k	0.00

Summaryinfo

A vulnerability, which was classified as problematic, was found in GNU tar up to 1.29. Affected by this issue is some unknown functionality of the component Extraction. Such manipulation leads to path traversal (Path). This vulnerability is documented as CVE-2016-6321. The attack can be executed remotely. Additionally, an exploit exists. The existence of this vulnerability is still disputed at present. You should upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, has been found in GNU tar up to 1.29. Affected by this issue is some unknown functionality of the component Extraction. The manipulation with an unknown input leads to a path traversal vulnerability (Path). Using CWE to declare the problem leads to CWE-22. The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory. Impacted is integrity, and availability.

The bug was discovered 03/10/2016. The weakness was released 10/27/2016 by Harry Sintonen as [CSS] POINTYFEATHER / tar extract pathname bypass (CVE-2016-6321) as confirmed mailinglist post (Full-Disclosure). The advisory is shared for download at seclists.org. The public release was coordinated with the vendor. This vulnerability is handled as CVE-2016-6321 since 07/26/2016. The attack needs to be approached locally. A simple authentication is required for exploitation. Technical details are unknown but a public exploit is available. The MITRE ATT&CK project declares the attack technique as T1006. The advisory points out:

GNU `tar' archiver 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.

A public exploit has been developed by Harry Sintonen in TAR and been published immediately after the advisory. The exploit is available at seclists.org. It is declared as proof-of-concept. The vulnerability was handled as a non-public zero-day exploit for at least 4863 days. During that time the estimated underground price was around $5k-$25k. The real existence of this vulnerability is still doubted at the moment. The vulnerability scanner Nessus provides a plugin with the ID 95270 (GLSA-201611-19 : Tar: Extract pathname bypass), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Gentoo Local Security Checks and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 169552 (OpenSuSE Security Update for tar (openSUSE-SU-2016:3003-1)).

Upgrading eliminates this vulnerability. A possible mitigation has been published 4 weeks after the disclosure of the vulnerability.

The vulnerability is also documented in the databases at Tenable (95270) and SecurityFocus (BID 93937†). Once again VulDB remains the best source for vulnerability data.

Productinfo

Vendor

Name

Version

License

open-source

Website

Vendor: https://www.gnu.org/

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.5
VulDB Meta Temp Score: 7.1

VulDB Base Score: 7.5
VulDB Temp Score: 6.7
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 7.5
NVD Vector: 🔍

CVSSv2info

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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
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NVD Base Score: 🔍

Exploitinginfo

Name: Path
Class: Path traversal / Path
CWE: CWE-22
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: Yes

Availability: 🔍
Access: Public
Status: Proof-of-Concept
Author: Harry Sintonen
Programming Language: 🔍
Download: 🔍

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 95270
Nessus Name: GLSA-201611-19 : Tar: Extract pathname bypass
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

OpenVAS ID: 703702
OpenVAS Name: Debian Security Advisory DSA 3702-1 (tar - security update)
OpenVAS File: 🔍
OpenVAS Family: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

Reaction Time: 🔍
0-Day Time: 🔍
Exposure Time: 🔍
Exploit Delay Time: 🔍

Patch: git.savannah.gnu.org

Timelineinfo

07/05/2003 🔍
03/10/2016 +4632 days 🔍
03/15/2016 +5 days 🔍
03/17/2016 +2 days 🔍
07/26/2016 +131 days 🔍
10/27/2016 +93 days 🔍
10/27/2016 +0 days 🔍
10/27/2016 +0 days 🔍
10/28/2016 +1 days 🔍
11/22/2016 +25 days 🔍
11/23/2016 +1 days 🔍
12/09/2016 +16 days 🔍
08/07/2025 +3162 days 🔍