GNU Bash 4.4 Path Autocompletion Metacharacter input validation

CVSS Meta Temp Score
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CTI Interest Score
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6.3$0-$5k0.00

Summaryinfo

A vulnerability was found in GNU Bash 4.4. It has been rated as critical. Affected by this issue is some unknown functionality of the component Path Autocompletion. This manipulation as part of Metacharacter causes input validation. This vulnerability is handled as CVE-2017-5932. It is possible to launch the attack on the local host. There is not any exploit available. It is suggested to install a patch to address this issue.

Detailsinfo

A vulnerability classified as critical was found in GNU Bash 4.4. Affected by this vulnerability is an unknown function of the component Path Autocompletion. The manipulation as part of a Metacharacter leads to a input validation vulnerability. The CWE definition for the vulnerability is CWE-20. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

The path autocompletion feature in Bash 4.4 allows local users to gain privileges via a crafted filename starting with a " (double quote) character and a command substitution metacharacter.

The bug was discovered 02/07/2017. The weakness was released 03/27/2017 by Jens Heyens (Website). The advisory is shared at lists.gnu.org. This vulnerability is known as CVE-2017-5932 since 02/07/2017. An attack has to be approached locally. The successful exploitation requires a single authentication. Neither technical details nor an exploit are publicly available.

The vulnerability was handled as a non-public zero-day exploit for at least 48 days. During that time the estimated underground price was around $0-$5k. The vulnerability scanner Nessus provides a plugin with the ID 100268 (Ubuntu 14.04 LTS / 16.04 LTS / 16.10 / 17.04 : bash vulnerabilities (USN-3294-1)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Ubuntu Local Security Checks and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 196789 (Ubuntu Security Notification for Bash Vulnerabilities (USN-3294-1)).

Applying a patch is able to eliminate this problem. The bugfix is ready for download at git.savannah.gnu.org. A possible mitigation has been published 2 months after the disclosure of the vulnerability.

The vulnerability is also documented in the databases at Tenable (100268) and SecurityFocus (BID 96136†). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.5
VulDB Meta Temp Score: 6.4

VulDB Base Score: 5.3
VulDB Temp Score: 5.1
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 7.8
NVD Vector: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Input validation
CWE: CWE-20
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: No

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 100268
Nessus Name: Ubuntu 14.04 LTS / 16.04 LTS / 16.10 / 17.04 : bash vulnerabilities (USN-3294-1)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

OpenVAS ID: 841810
OpenVAS Name: Ubuntu Update for bash USN-3294-1
OpenVAS File: 🔍
OpenVAS Family: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Patch
Status: 🔍

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

Patch: git.savannah.gnu.org

Timelineinfo

02/07/2017 🔍
02/07/2017 +0 days 🔍
02/07/2017 +0 days 🔍
03/27/2017 +48 days 🔍
03/27/2017 +0 days 🔍
03/28/2017 +1 days 🔍
05/17/2017 +50 days 🔍
05/18/2017 +1 days 🔍
08/23/2020 +1193 days 🔍

Sourcesinfo

Vendor: gnu.org

Advisory: lists.gnu.org
Researcher: Jens Heyens
Status: Not defined
Confirmation: 🔍

CVE: CVE-2017-5932 (🔍)
GCVE (CVE): GCVE-0-2017-5932
GCVE (VulDB): GCVE-100-99001
SecurityFocus: 96136 - GNU Bash CVE-2017-5932 Multiple Arbitrary Code Execution Vulnerabilities
OSVDB: - CVE-2017-5932 - Bash - Privilege Escalation Issue

Entryinfo

Created: 03/28/2017 22:05
Updated: 08/23/2020 14:15
Changes: 03/28/2017 22:05 (81), 08/23/2020 14:15 (3)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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