ID

VAR-201409-1156

CVE

CVE-2014-6271

TITLE

GNU Bash shell executes commands in exported functions in environment variables

DESCRIPTION

GNU Bash through 4.3 processes trailing strings after function definitions in the values of environment variables, which allows remote attackers to execute arbitrary code via a crafted environment, as demonstrated by vectors involving the ForceCommand feature in OpenSSH sshd, the mod_cgi and mod_cgid modules in the Apache HTTP Server, scripts executed by unspecified DHCP clients, and other situations in which setting the environment occurs across a privilege boundary from Bash execution, aka "ShellShock." NOTE: the original fix for this issue was incorrect; CVE-2014-7169 has been assigned to cover the vulnerability that is still present after the incorrect fix. GNU Bash 4.3 and earlier contains a command injection vulnerability that may allow remote code execution. An attacker can exploit this issue to execute arbitrary code within the context of the affected application. Failed exploit attempts will result in a denial-of-service condition. -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 ===================================================================== Red Hat Security Advisory Synopsis: Critical: bash Shift_JIS security update Advisory ID: RHSA-2014:1295-01 Product: RHEL S-JIS Service Advisory URL: https://rhn.redhat.com/errata/RHSA-2014-1295.html Issue date: 2014-09-24 CVE Names: CVE-2014-6271 ===================================================================== 1. Summary: Updated bash Shift_JIS packages that fix one security issue are now available for Red Hat Enterprise Linux 5 and 6. Red Hat Product Security has rated this update as having Critical security impact. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available from the CVE link in the References section. 2. Relevant releases/architectures: SJIS (v. 5.11.z Server) - i386, ia64, x86_64 SJIS for RHEL 6 Server - i386, x86_64 3. Description: The GNU Bourne Again shell (Bash) is a shell and command language interpreter compatible with the Bourne shell (sh). Bash is the default shell for Red Hat Enterprise Linux. Shift_JIS, also known as "SJIS", is a character encoding for the Japanese language. This package provides bash support for the Shift_JIS encoding. 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) For additional information on the CVE-2014-6271 flaw, refer to the Knowledgebase article at https://access.redhat.com/articles/1200223 Red Hat would like to thank Stephane Chazelas for reporting this issue. All users who require Shift_JIS encoding support with Bash built-in functions are advised to upgrade to these updated packages, which contain a backported patch to correct this issue. 4. Solution: Before applying this update, make sure all previously released errata relevant to your system have been applied. This update is available via the Red Hat Network. Details on how to use the Red Hat Network to apply this update are available at https://access.redhat.com/articles/11258 5. Bugs fixed (https://bugzilla.redhat.com/): 1141597 - CVE-2014-6271 bash: specially-crafted environment variables can be used to inject shell commands 6. Package List: SJIS (v. 5.11.z Server): Source: bash-3.2-33.el5_11.1.sjis.1.src.rpm i386: bash-3.2-33.el5_11.1.sjis.1.i386.rpm bash-debuginfo-3.2-33.el5_11.1.sjis.1.i386.rpm ia64: bash-3.2-33.el5_11.1.sjis.1.i386.rpm bash-3.2-33.el5_11.1.sjis.1.ia64.rpm bash-debuginfo-3.2-33.el5_11.1.sjis.1.i386.rpm bash-debuginfo-3.2-33.el5_11.1.sjis.1.ia64.rpm x86_64: bash-3.2-33.el5_11.1.sjis.1.x86_64.rpm bash-debuginfo-3.2-33.el5_11.1.sjis.1.x86_64.rpm SJIS for RHEL 6 Server: Source: bash-4.1.2-15.el6_5.1.sjis.1.src.rpm i386: bash-4.1.2-15.el6_5.1.sjis.1.i686.rpm bash-debuginfo-4.1.2-15.el6_5.1.sjis.1.i686.rpm bash-doc-4.1.2-15.el6_5.1.sjis.1.i686.rpm x86_64: bash-4.1.2-15.el6_5.1.sjis.1.x86_64.rpm bash-debuginfo-4.1.2-15.el6_5.1.sjis.1.x86_64.rpm bash-doc-4.1.2-15.el6_5.1.sjis.1.x86_64.rpm These packages are GPG signed by Red Hat for security. Our key and details on how to verify the signature are available from https://access.redhat.com/security/team/key/#package 7. References: https://www.redhat.com/security/data/cve/CVE-2014-6271.html https://access.redhat.com/security/updates/classification/#critical https://access.redhat.com/articles/1200223 8. Contact: The Red Hat security contact is <secalert@redhat.com>. More contact details at https://access.redhat.com/security/team/contact/ Copyright 2014 Red Hat, Inc. This vulnerability allows users that have been granted access to a shell script to escalate privilege and execute unrestricted commands at the same security level as the Bash script. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Gentoo Linux Security Advisory GLSA 201409-09 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - http://security.gentoo.org/ - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Severity: High Title: Bash: Code Injection Date: September 24, 2014 Bugs: #523592 ID: 201409-09 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Synopsis ======== A parsing flaw related to functions and environments in Bash could allow attackers to inject code. Affected packages ================= ------------------------------------------------------------------- Package / Vulnerable / Unaffected ------------------------------------------------------------------- 1 app-shells/bash < 4.2_p48 *>= 3.1_p18 *>= 3.2_p52 *>= 4.0_p39 *>= 4.1_p12 >= 4.2_p48 Description =========== Stephane Chazelas reported that Bash incorrectly handles function definitions, allowing attackers to inject arbitrary code. Workaround ========== There is no known workaround at this time. Resolution ========== All Bash 3.1 users should upgrade to the latest version: # emerge --sync # emerge --ask --oneshot --verbose ">=app-shells/bash-3.1_p18" All Bash 3.2 users should upgrade to the latest version: # emerge --sync # emerge --ask --oneshot --verbose ">=app-shells/bash-3.2_p52" All Bash 4.0 users should upgrade to the latest version: # emerge --sync # emerge --ask --oneshot --verbose ">=app-shells/bash-4.0_p39" All Bash 4.1 users should upgrade to the latest version: # emerge --sync # emerge --ask --oneshot --verbose ">=app-shells/bash-4.1_p12" All Bash 4.2 users should upgrade to the latest version: # emerge --sync # emerge --ask --oneshot --verbose ">=app-shells/bash-4.2_p48" References ========== [ 1 ] CVE-2014-6271 http://nvd.nist.gov/nvd.cfm?cvename=CVE-2014-6271 Availability ============ This GLSA and any updates to it are available for viewing at the Gentoo Security Website: http://security.gentoo.org/glsa/glsa-201409-09.xml Concerns? ========= Security is a primary focus of Gentoo Linux and ensuring the confidentiality and security of our users' machines is of utmost importance to us. Any security concerns should be addressed to security@gentoo.org or alternatively, you may file a bug at https://bugs.gentoo.org. License ======= Copyright 2014 Gentoo Foundation, Inc; referenced text belongs to its owner(s). The contents of this document are licensed under the Creative Commons - Attribution / Share Alike license. http://creativecommons.org/licenses/by-sa/2.5 . Bash shipped with GNV 3.0-1 and previous versions are impacted by .Shellshock. vulnerability. HP GNV Website: http://h71000.www7.hp.com/opensource/gnv.html Sourceforge: IA64: https://sourceforge.net/projects/gnv/files/GNV%20-%20I64/V3.0-1/ Alpha: https://sourceforge.net/projects/gnv/files/GNV%20-%20Alpha/V3.0-1/ HP Bash Version for OpenVMS Platform Patch Kit Name v1.14-8 Alpha OpenVMS V8.3, V8.4 HP-AXPVMS-GNV-BASH-V0114-08.ZIP v1.14-8 ITANIUM OpenVMS V8.3, V8.3-1H1, V8.4 HP-AXPVMS-GNV-BASH-V0114-08.ZIP HISTORY Version:1 (rev.1) - 12 January 2015 Initial release Support: For further information, contact normal HP Services support channel. Under Step2: your ITRC operating systems - verify your operating system selections are checked and save. To update an existing subscription: http://h30046.www3.hp.com/subSignIn.php Log in on the web page: Subscriber's choice for Business: sign-in. On the web page: Subscriber's Choice: your profile summary - use Edit Profile to update appropriate sections. HP is continually reviewing and enhancing the security features of software products to provide customers with current secure solutions. "HP is broadly distributing this Security Bulletin in order to bring to the attention of users of the affected HP products the important security information contained in this Bulletin. HP recommends that all users determine the applicability of this information to their individual situations and take appropriate action. HP does not warrant that this information is necessarily accurate or complete for all user situations and, consequently, HP will not be responsible for any damages resulting from user's use or disregard of the information provided in this Bulletin. To the extent permitted by law, HP disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose, title and non-infringement." Copyright 2015 Hewlett-Packard Development Company, L.P. -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Note: the current version of the following document is available here: https://h20564.www2.hp.com/portal/site/hpsc/public/kb/ docDisplay?docId=emr_na-c04467807 SUPPORT COMMUNICATION - SECURITY BULLETIN Document ID: c04467807 Version: 1 HPSBGN03117 rev.1 - HP Remote Device Access: Virtual Customer Access System (vCAS) running Bash Shell, Remote Code Execution NOTICE: The information in this Security Bulletin should be acted upon as soon as possible. Release Date: 2014-09-30 Last Updated: 2014-09-30 Potential Security Impact: Remote code execution Source: Hewlett-Packard Company, HP Software Security Response Team VULNERABILITY SUMMARY A potential security vulnerability has been identified with HP Remote Device Access: Virtual Customer Access System (vCAS) running Bash Shell . NOTE: The vCAS product is vulnerable only if DHCP is enabled. References: CVE-2014-6271 CVE-2014-7169 SSRT101724 SUPPORTED SOFTWARE VERSIONS*: ONLY impacted versions are listed. vCAS version 14.06 (RDA 8.1) BACKGROUND CVSS 2.0 Base Metrics =========================================================== Reference Base Vector Base Score CVE-2014-6271 (AV:N/AC:L/Au:N/C:C/I:C/A:C) 10.0 CVE-2014-7169 (AV:N/AC:L/Au:N/C:C/I:C/A:C) 10.0 =========================================================== Information on CVSS is documented in HP Customer Notice: HPSN-2008-002 RESOLUTION HP is actively working to address this vulnerability for the impacted product versions of HP Remote Device Access: Virtual Customer Access System (vCAS) running Bash Shell. This bulletin will be revised when the software update is released. NOTE: HP recommends to not power-down or disconnect the vCAS until the update is available. MITIGATION INFORMATION A Shellshock attack requires the definition of an environment variable introduced into Bash. The vCAS has three attack vectors: SSH, the lighttpd web server, and the DHCP client. - The exploit does not elevate privileges. The DHCP client uses Bash scripts and is vulnerable to Shellshock. The DHCP exploit can be mitigated by ensuring that DHCP is disabled on the vCAS. Note: HP strongly discourages the use of DHCP on the vCAS. The web UI forces the vCAS user to assign a static IP address and change the hp-admin password. A vCAS user must manually configure DHCP for use on the vCAS. A vCAS user can verify that DHCP is disabled by inspecting the file "/etc/network/interfaces" and ensuring that the "iface" line for device "eth0" is set for a static IP. Example of a static IP configuration: # The primary network interface auto eth0 iface eth0 inet static address 172.27.1.68 netmask 255.255.255.0 gateway 172.27.1.1 HISTORY Version:1 (rev.1) - 30 September 2014 Initial release Third Party Security Patches: Third party security patches that are to be installed on systems running HP software products should be applied in accordance with the customer's patch management policy. Support: For issues about implementing the recommendations of this Security Bulletin, contact normal HP Services support channel. For other issues about the content of this Security Bulletin, send e-mail to security-alert@hp.com. Report: To report a potential security vulnerability with any HP supported product, send Email to: security-alert@hp.com Subscribe: To initiate a subscription to receive future HP Security Bulletin alerts via Email: http://h41183.www4.hp.com/signup_alerts.php?jumpid=hpsc_secbulletins Security Bulletin Archive: A list of recently released Security Bulletins is available here: https://h20564.www2.hp.com/portal/site/hpsc/public/kb/secBullArchive/ Software Product Category: The Software Product Category is represented in the title by the two characters following HPSB. 3C = 3COM 3P = 3rd Party Software GN = HP General Software HF = HP Hardware and Firmware MP = MPE/iX MU = Multi-Platform Software NS = NonStop Servers OV = OpenVMS PI = Printing and Imaging PV = ProCurve ST = Storage Software TU = Tru64 UNIX UX = HP-UX Copyright 2014 Hewlett-Packard Development Company, L.P. Hewlett-Packard Company shall not be liable for technical or editorial errors or omissions contained herein. The information provided is provided "as is" without warranty of any kind. To the extent permitted by law, neither HP or its affiliates, subcontractors or suppliers will be liable for incidental,special or consequential damages including downtime cost; lost profits; damages relating to the procurement of substitute products or services; or damages for loss of data, or software restoration. The information in this document is subject to change without notice. Hewlett-Packard Company and the names of Hewlett-Packard products referenced herein are trademarks of Hewlett-Packard Company in the United States and other countries. Other product and company names mentioned herein may be trademarks of their respective owners. -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.19 (GNU/Linux) iEYEARECAAYFAlQrBP4ACgkQ4B86/C0qfVmXyQCfcKhAA0uY3dImfSwtEVk8Za3c vj4AnjNi4SmLcQFrPcGjdzRDt8U1OGS/ =6Tia -----END PGP SIGNATURE-----

AFFECTED PRODUCTS