popd in bash might allow local users to bypass the restricted shell and cause a use-after-free via a crafted address.

The remote NewStart CGSL host, running version MAIN 4.05, has bash packages installed that are affected by multiple vulnerabilities:

  - A denial of service flaw was found in the way bash     handled popd commands. A poorly written shell script     could cause bash to crash resulting in a local denial of     service limited to a specific bash session.
    (CVE-2016-9401)

  - An arbitrary command injection flaw was found in the way     bash processed the SHELLOPTS and PS4 environment     variables. A local, authenticated attacker could use     this flaw to exploit poorly written setuid programs to     elevate their privileges under certain circumstances.
    (CVE-2016-7543)

  - An arbitrary command injection flaw was found in the way     bash processed the hostname value. A malicious DHCP     server could use this flaw to execute arbitrary commands     on the DHCP client machines running bash under specific     circumstances. (CVE-2016-0634)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

According to the versions of the bash package installed, the EulerOS Virtualization installation on the remote host is affected by the following vulnerabilities :

  - It was found that the fix for CVE-2014-6271 was     incomplete, and Bash still allowed certain characters     to be injected into other environments via specially     crafted environment variables. An attacker could     potentially use this flaw to override or bypass     environment restrictions to execute shell commands.
    Certain services and applications allow remote     unauthenticated attackers to provide environment     variables, allowing them to exploit this     issue.(CVE-2014-7169)

  - A denial of service flaw was found in the way bash     handled popd commands. A poorly written shell script     could cause bash to crash resulting in a local denial     of service limited to a specific bash     session.(CVE-2016-9401)

  - It was discovered that the fixed-sized redir_stack     could be forced to overflow in the Bash parser,     resulting in memory corruption, and possibly leading to     arbitrary code execution when evaluating untrusted     input that would not otherwise be run as     code.(CVE-2014-7186)

  - An off-by-one error was discovered in the way Bash was     handling deeply nested flow control constructs.
    Depending on the layout of the .bss segment, this could     allow arbitrary execution of code that would not     otherwise be executed by Bash.(CVE-2014-7187)

  - A flaw was found in the way Bash evaluated certain     specially crafted environment variables. An attacker     could use this flaw to override or bypass environment     restrictions to execute shell commands. Certain     services and applications allow remote unauthenticated     attackers to provide environment variables, allowing     them to exploit this issue.(CVE-2014-6271)

  - An arbitrary command injection flaw was found in the     way bash processed the SHELLOPTS and PS4 environment     variables. A local, authenticated attacker could use     this flaw to exploit poorly written setuid programs to     elevate their privileges under certain     circumstances.(CVE-2016-7543)

Note that Tenable Network Security has extracted the preceding description block directly from the EulerOS security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

Two issues have been fixed in bash, the GNU Bourne-Again Shell :

CVE-2016-9401

The popd builtin segfaulted when called with negative out of range offsets.

CVE-2019-9924

Sylvain Beucler discovered that it was possible to call commands that contained a slash when in restricted mode (rbash) by adding them to the BASH_CMDS array.

For Debian 8 'Jessie', these problems have been fixed in version 4.3-11+deb8u2.

We recommend that you upgrade your bash 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.

An update of the bash package has been released.

According to the versions of the bash package installed, the EulerOS installation on the remote host is affected by the following vulnerabilities :

  - An arbitrary command injection flaw was found in the     way bash processed the hostname value. A malicious DHCP     server could use this flaw to execute arbitrary     commands on the DHCP client machines running bash under     specific circumstances. (CVE-2016-0634)

  - An arbitrary command injection flaw was found in the     way bash processed the SHELLOPTS and PS4 environment     variables. A local, authenticated attacker could use     this flaw to exploit poorly written setuid programs to     elevate their privileges under certain circumstances.
    (CVE-2016-7543)

  - A denial of service flaw was found in the way bash     handled popd commands. A poorly written shell script     could cause bash to crash resulting in a local denial     of service limited to a specific bash session.
    (CVE-2016-9401)

Note that Tenable Network Security has extracted the preceding description block directly from the EulerOS security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

popd controlled free :

A denial of service flaw was found in the way bash handled popd commands. A poorly written shell script could cause bash to crash resulting in a local denial of service limited to a specific bash session.(CVE-2016-9401)

Arbitrary code execution via malicious hostname :

An arbitrary command injection flaw was found in the way bash processed the hostname value. A malicious DHCP server could use this flaw to execute arbitrary commands on the DHCP client machines running bash under specific circumstances.(CVE-2016-0634)

Specially crafted SHELLOPTS+PS4 variables allows command substitution :

An arbitrary command injection flaw was found in the way bash processed the SHELLOPTS and PS4 environment variables. A local, authenticated attacker could use this flaw to exploit poorly written setuid programs to elevate their privileges under certain circumstances. (CVE-2016-7543)

An update for bash is now available for Red Hat Enterprise Linux 7.

Red Hat Product Security has rated this update as having a security impact of Moderate. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

The bash packages provide Bash (Bourne-again shell), which is the default shell for Red Hat Enterprise Linux.

Security Fix(es) :

* An arbitrary command injection flaw was found in the way bash processed the hostname value. A malicious DHCP server could use this flaw to execute arbitrary commands on the DHCP client machines running bash under specific circumstances. (CVE-2016-0634)

* An arbitrary command injection flaw was found in the way bash processed the SHELLOPTS and PS4 environment variables. A local, authenticated attacker could use this flaw to exploit poorly written setuid programs to elevate their privileges under certain circumstances. (CVE-2016-7543)

* A denial of service flaw was found in the way bash handled popd commands. A poorly written shell script could cause bash to crash resulting in a local denial of service limited to a specific bash session. (CVE-2016-9401)

Additional Changes :

For detailed information on changes in this release, see the Red Hat Enterprise Linux 7.4 Release Notes linked from the References section.

Security Fix(es) :

  - An arbitrary command injection flaw was found in the way     bash processed the hostname value. A malicious DHCP     server could use this flaw to execute arbitrary commands     on the DHCP client machines running bash under specific     circumstances. (CVE-2016-0634)

  - An arbitrary command injection flaw was found in the way     bash processed the SHELLOPTS and PS4 environment     variables. A local, authenticated attacker could use     this flaw to exploit poorly written setuid programs to     elevate their privileges under certain circumstances.
    (CVE-2016-7543)

  - A denial of service flaw was found in the way bash     handled popd commands. A poorly written shell script     could cause bash to crash resulting in a local denial of     service limited to a specific bash session.
    (CVE-2016-9401)

From Red Hat Security Advisory 2017:1931 :

An update for bash is now available for Red Hat Enterprise Linux 7.

Red Hat Product Security has rated this update as having a security impact of Moderate. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

The bash packages provide Bash (Bourne-again shell), which is the default shell for Red Hat Enterprise Linux.

Security Fix(es) :

* An arbitrary command injection flaw was found in the way bash processed the hostname value. A malicious DHCP server could use this flaw to execute arbitrary commands on the DHCP client machines running bash under specific circumstances. (CVE-2016-0634)

* An arbitrary command injection flaw was found in the way bash processed the SHELLOPTS and PS4 environment variables. A local, authenticated attacker could use this flaw to exploit poorly written setuid programs to elevate their privileges under certain circumstances. (CVE-2016-7543)

* A denial of service flaw was found in the way bash handled popd commands. A poorly written shell script could cause bash to crash resulting in a local denial of service limited to a specific bash session. (CVE-2016-9401)

Additional Changes :

For detailed information on changes in this release, see the Red Hat Enterprise Linux 7.4 Release Notes linked from the References section.

This update for bash fixes an issue that could lead to syntax errors when parsing scripts that use expr(1) inside loops.

Additionally, the popd build-in now ensures that the normalized stack offset is within bounds before trying to free that stack entry. This fixes a segmentation fault.

This update was imported from the SUSE:SLE-12-SP2:Update update project.

This update for bash fixed several issues This security issue was fixed :

  - CVE-2016-9401: popd in bash might allowed local users to     bypass the restricted shell and cause a use-after-free     via a crafted address (bsc#1010845).

The update package also includes non-security fixes. See advisory for details.

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.

Bernd Dietzel discovered that Bash incorrectly expanded the hostname when displaying the prompt. If a remote attacker were able to modify a hostname, this flaw could be exploited to execute arbitrary code. This issue only affected Ubuntu 14.04 LTS, Ubuntu 16.04 LTS and Ubuntu 16.10. (CVE-2016-0634)

It was discovered that Bash incorrectly handled the SHELLOPTS and PS4 environment variables. A local attacker could use this issue to execute arbitrary code with root privileges. This issue only affected Ubuntu 14.04 LTS, Ubuntu 16.04 LTS and Ubuntu 16.10. (CVE-2016-7543)

It was discovered that Bash incorrectly handled the popd command. A remote attacker could possibly use this issue to bypass restricted shells. (CVE-2016-9401)

It was discovered that Bash incorrectly handled path autocompletion. A local attacker could possibly use this issue to execute arbitrary code. This issue only affected Ubuntu 17.04. (CVE-2017-5932).

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.

This update for bash fixes an issue that could lead to syntax errors when parsing scripts that use expr(1) inside loops. Additionally, the popd build-in now ensures that the normalized stack offset is within bounds before trying to free that stack entry. This fixes a segmentation fault.

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.

The remote OracleVM system is missing necessary patches to address critical security updates :

  - Fix signal handling in read builtin Resolves: #1421926

  - CVE-2016-9401 - Fix crash when '-' is passed as second     sign to popd Resolves: #1396383

  - CVE-2016-7543 - Fix for arbitrary code execution via     SHELLOPTS+PS4 variables Resolves: #1379630

  - CVE-2016-0634 - Fix for arbitrary code execution via     malicious hostname Resolves: #1377613

  - Avoid crash in parameter expansion while expanding long     strings Resolves: #1359142

  - Stop reading input when SIGHUP is received Resolves:
    #1325753

  - Bash leaks memory while doing pattern removal in     parameter expansion Resolves: #1283829

  - Fix a race condition in saving bash history on shutdown     Resolves: #1325753

  - Bash shouldn't ignore bash --debugger without a dbger     installed Related: #1260568

  - Wrong parsing inside for loop and brackets Resolves:
    #1207803

  - IFS incorrectly splitting herestrings Resolves: #1250070

  - Case in a for loop in a subshell causes a syntax error     Resolves: #1240994

  - Bash shouldn't ignore bash --debugger without a dbger     installed Resolves: #1260568

  - Bash leaks memory when repeatedly doing a pattern-subst     Resolves: #1207042

  - Bash hangs when a signal is received Resolves: #868846

From Red Hat Security Advisory 2017:0725 :

An update for bash is now available for Red Hat Enterprise Linux 6.

Red Hat Product Security has rated this update as having a security impact of Moderate. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

The bash packages provide Bash (Bourne-again shell), which is the default shell for Red Hat Enterprise Linux.

Security Fix(es) :

* An arbitrary command injection flaw was found in the way bash processed the hostname value. A malicious DHCP server could use this flaw to execute arbitrary commands on the DHCP client machines running bash under specific circumstances. (CVE-2016-0634)

* An arbitrary command injection flaw was found in the way bash processed the SHELLOPTS and PS4 environment variables. A local, authenticated attacker could use this flaw to exploit poorly written setuid programs to elevate their privileges under certain circumstances. (CVE-2016-7543)

* A denial of service flaw was found in the way bash handled popd commands. A poorly written shell script could cause bash to crash resulting in a local denial of service limited to a specific bash session. (CVE-2016-9401)

Additional Changes :

For detailed information on changes in this release, see the Red Hat Enterprise Linux 6.9 Release Notes and Red Hat Enterprise Linux 6.9 Technical Notes linked from the References section.

An update for bash is now available for Red Hat Enterprise Linux 6.

Red Hat Product Security has rated this update as having a security impact of Moderate. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

The bash packages provide Bash (Bourne-again shell), which is the default shell for Red Hat Enterprise Linux.

Security Fix(es) :

* An arbitrary command injection flaw was found in the way bash processed the hostname value. A malicious DHCP server could use this flaw to execute arbitrary commands on the DHCP client machines running bash under specific circumstances. (CVE-2016-0634)

* An arbitrary command injection flaw was found in the way bash processed the SHELLOPTS and PS4 environment variables. A local, authenticated attacker could use this flaw to exploit poorly written setuid programs to elevate their privileges under certain circumstances. (CVE-2016-7543)

* A denial of service flaw was found in the way bash handled popd commands. A poorly written shell script could cause bash to crash resulting in a local denial of service limited to a specific bash session. (CVE-2016-9401)

Additional Changes :

For detailed information on changes in this release, see the Red Hat Enterprise Linux 6.9 Release Notes and Red Hat Enterprise Linux 6.9 Technical Notes linked from the References section.

The remote host is affected by the vulnerability described in GLSA-201701-02 (Bash: Multiple vulnerabilities)

    Multiple vulnerabilities have been discovered in Bash. Please review the       CVE identifiers referenced below for details.
  Impact :

    A local attacker could possibly execute arbitrary code with the       privileges of the process, or cause a Denial of Service condition.
  Workaround :

    There is no known workaround at this time.

ID	Name	Product	Family	Severity
127342	NewStart CGSL MAIN 4.05 : bash Multiple Vulnerabilities (NS-SA-2019-0108)	Nessus	NewStart CGSL Local Security Checks	high
124921	EulerOS Virtualization 3.0.1.0 : bash (EulerOS-SA-2019-1418)	Nessus	Huawei Local Security Checks	critical
123093	Debian DLA-1726-1 : bash security update	Nessus	Debian Local Security Checks	high
121760	Photon OS 2.0: Bash PHSA-2017-0045	Nessus	PhotonOS Local Security Checks	medium
121755	Photon OS 1.0: Bash PHSA-2017-0044	Nessus	PhotonOS Local Security Checks	medium
103002	EulerOS 2.0 SP2 : bash (EulerOS-SA-2017-1164)	Nessus	Huawei Local Security Checks	high
103001	EulerOS 2.0 SP1 : bash (EulerOS-SA-2017-1163)	Nessus	Huawei Local Security Checks	high
102866	Amazon Linux AMI : bash (ALAS-2017-878)	Nessus	Amazon Linux Local Security Checks	high
102744	CentOS 7 : bash (CESA-2017:1931)	Nessus	CentOS Local Security Checks	high
102638	Scientific Linux Security Update : bash on SL7.x x86_64 (20170801)	Nessus	Scientific Linux Local Security Checks	high
102289	Oracle Linux 7 : bash (ELSA-2017-1931)	Nessus	Oracle Linux Local Security Checks	high
102105	RHEL 7 : bash (RHSA-2017:1931)	Nessus	Red Hat Local Security Checks	high
100395	openSUSE Security Update : bash (openSUSE-2017-614)	Nessus	SuSE Local Security Checks	medium
100292	SUSE SLES11 Security Update : bash (SUSE-SU-2017:1337-1)	Nessus	SuSE Local Security Checks	medium
100268	Ubuntu 14.04 LTS / 16.04 LTS : Bash vulnerabilities (USN-3294-1)	Nessus	Ubuntu Local Security Checks	high
100246	SUSE SLED12 / SLES12 Security Update : bash (SUSE-SU-2017:1317-1)	Nessus	SuSE Local Security Checks	medium
99214	Scientific Linux Security Update : bash on SL6.x i386/x86_64 (20170321)	Nessus	Scientific Linux Local Security Checks	high
99077	OracleVM 3.3 / 3.4 : bash (OVMSA-2017-0050)	Nessus	OracleVM Local Security Checks	high
99071	Oracle Linux 6 : bash (ELSA-2017-0725)	Nessus	Oracle Linux Local Security Checks	high
97959	CentOS 6 : bash (CESA-2017:0725)	Nessus	CentOS Local Security Checks	high
97883	RHEL 6 : bash (RHSA-2017:0725)	Nessus	Red Hat Local Security Checks	high
96233	GLSA-201701-02 : Bash: Multiple vulnerabilities	Nessus	Gentoo Local Security Checks	high

Detections

Analytics

CVE-2016-9401

medium

Tenable Plugins

high

critical

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