GNU Bash 4.3 \h Expansion Hostname os command injection

CVSS Meta Temp Score
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CTI Interest Score
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8.2$0-$5k0.00

Summaryinfo

A vulnerability identified as problematic has been detected in GNU Bash 4.3. This impacts an unknown function of the component \h Expansion. Performing a manipulation of the argument Hostname results in os command injection. This vulnerability is reported as CVE-2016-0634. The attack requires a local approach. No exploit exists. You should upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, was found in GNU Bash 4.3. This affects some unknown functionality of the component \h Expansion. The manipulation of the argument hostname with an unknown input leads to a os command injection vulnerability. CWE is classifying the issue as CWE-78. The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

The expansion of '\h' in the prompt string in bash 4.3 allows remote authenticated users to execute arbitrary code via shell metacharacters placed in 'hostname' of a machine.

The bug was discovered 09/16/2016. The weakness was disclosed 08/28/2017 by John Haxby (oss-sec). It is possible to read the advisory at openwall.com. This vulnerability is uniquely identified as CVE-2016-0634 since 12/09/2015. The exploitability is told to be easy. Attacking locally is a requirement. No form of authentication is needed for exploitation. Technical details of the vulnerability are known, but there is no available exploit. The attack technique deployed by this issue is T1202 according to MITRE ATT&CK.

The vulnerability was handled as a non-public zero-day exploit for at least 189 days. During that time the estimated underground price was around $0-$5k. The vulnerability scanner Nessus provides a plugin with the ID 97959 (CentOS 6 : bash (CESA-2017:0725)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family CentOS Local Security Checks and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 169385 (SUSE Enterprise Linux Security Update for bash (SUSE-SU-2016:2872-1)).

Upgrading eliminates this vulnerability. A possible mitigation has been published even before and not after the disclosure of the vulnerability.

The vulnerability is also documented in the databases at Tenable (97959) and SecurityFocus (BID 92999†). Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.4
VulDB Meta Temp Score: 8.2

VulDB Base Score: 9.3
VulDB Temp Score: 8.9
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 7.5
NVD Vector: 🔍

CVSSv2info

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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Os command injection
CWE: CWE-78 / CWE-77 / CWE-74
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 97959
Nessus Name: CentOS 6 : bash (CESA-2017:0725)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

OpenVAS ID: 867773
OpenVAS Name: Fedora Update for bash FEDORA-2016-eda100d886
OpenVAS File: 🔍
OpenVAS Family: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Timelineinfo

12/09/2015 🔍
09/16/2016 +282 days 🔍
09/16/2016 +0 days 🔍
03/24/2017 +189 days 🔍
03/27/2017 +3 days 🔍
08/28/2017 +154 days 🔍
08/28/2017 +0 days 🔍
08/29/2017 +1 days 🔍
12/16/2022 +1935 days 🔍

Sourcesinfo

Vendor: gnu.org

Advisory: RHSA-2017:0725
Researcher: John Haxby
Status: Not defined
Confirmation: 🔍

CVE: CVE-2016-0634 (🔍)
GCVE (CVE): GCVE-0-2016-0634
GCVE (VulDB): GCVE-100-105807
SecurityFocus: 92999 - GNU Bash CVE-2016-0634 Local Code Execution Vulnerability

Entryinfo

Created: 08/29/2017 10:30
Updated: 12/16/2022 18:43
Changes: 08/29/2017 10:30 (70), 11/10/2019 18:02 (9), 12/16/2022 18:43 (4)
Complete: 🔍
Cache ID: 216::103

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