ID CVE-2014-6271
Summary 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.
References
Vulnerable Configurations
  • GNU Bourne-Again SHellbash (GNU Bash) 1.14.0
    cpe:2.3:a:gnu:bash:1.14.0
  • GNU Bourne-Again SHellbash (GNU Bash) 1.14.1
    cpe:2.3:a:gnu:bash:1.14.1
  • GNU Bourne-Again SHellbash (GNU Bash) 1.14.2
    cpe:2.3:a:gnu:bash:1.14.2
  • GNU Bourne-Again SHellbash (GNU Bash) 1.14.3
    cpe:2.3:a:gnu:bash:1.14.3
  • GNU Bourne-Again SHellbash (GNU Bash) 1.14.4
    cpe:2.3:a:gnu:bash:1.14.4
  • GNU Bourne-Again SHellbash (GNU Bash) 1.14.5
    cpe:2.3:a:gnu:bash:1.14.5
  • GNU Bourne-Again SHellbash (GNU Bash) 1.14.6
    cpe:2.3:a:gnu:bash:1.14.6
  • GNU Bourne-Again SHellbash (GNU Bash) 1.14.7
    cpe:2.3:a:gnu:bash:1.14.7
  • GNU Bourne-Again SHellbash (GNU Bash) 2.0
    cpe:2.3:a:gnu:bash:2.0
  • GNU Bourne-Again SHellbash (GNU Bash) 2.01
    cpe:2.3:a:gnu:bash:2.01
  • GNU Bourne-Again SHellbash (GNU Bash) 2.01.1
    cpe:2.3:a:gnu:bash:2.01.1
  • GNU Bourne-Again SHellbash (GNU Bash) 2.02
    cpe:2.3:a:gnu:bash:2.02
  • GNU Bourne-Again SHellbash (GNU Bash) 2.02.1
    cpe:2.3:a:gnu:bash:2.02.1
  • GNU Bourne-Again SHellbash (GNU Bash) 2.03
    cpe:2.3:a:gnu:bash:2.03
  • GNU Bourne-Again SHellbash (GNU Bash) 2.04
    cpe:2.3:a:gnu:bash:2.04
  • GNU Bourne-Again SHellbash (GNU Bash) 2.05
    cpe:2.3:a:gnu:bash:2.05
  • GNU Bourne-Again SHellbash (GNU Bash) 2.05a
    cpe:2.3:a:gnu:bash:2.05:a
  • GNU Bourne-Again SHellbash (GNU Bash) 2.05b
    cpe:2.3:a:gnu:bash:2.05:b
  • GNU Bourne-Again SHellbash (GNU Bash) 3.0
    cpe:2.3:a:gnu:bash:3.0
  • GNU Bourne-Again SHellbash (GNU Bash) 3.0.16
    cpe:2.3:a:gnu:bash:3.0.16
  • GNU Bourne-Again SHellbash (GNU Bash) 3.1
    cpe:2.3:a:gnu:bash:3.1
  • GNU Bourne-Again SHellbash (GNU Bash) 3.2
    cpe:2.3:a:gnu:bash:3.2
  • GNU Bourne-Again SHellbash (GNU Bash) 3.2.48
    cpe:2.3:a:gnu:bash:3.2.48
  • GNU Bourne-Again SHellbash (GNU Bash) 4.0
    cpe:2.3:a:gnu:bash:4.0
  • GNU Bourne-Again SHellbash (GNU Bash) 4.0 release candidate 1
    cpe:2.3:a:gnu:bash:4.0:rc1
  • GNU Bourne-Again SHellbash (GNU Bash) 4.1
    cpe:2.3:a:gnu:bash:4.1
  • GNU Bourne-Again SHellbash (GNU Bash) 4.2
    cpe:2.3:a:gnu:bash:4.2
  • cpe:2.3:a:gnu:bash:4.3
    cpe:2.3:a:gnu:bash:4.3
CVSS
Base: 10.0 (as of 24-06-2016 - 12:25)
Impact:
Exploitability:
CWE CWE-78
CAPEC
  • Command Line Execution through SQL Injection
    An attacker uses standard SQL injection methods to inject data into the command line for execution. This could be done directly through misuse of directives such as MSSQL_xp_cmdshell or indirectly through injection of data into the database that would be interpreted as shell commands. Sometime later, an unscrupulous backend application (or could be part of the functionality of the same application) fetches the injected data stored in the database and uses this data as command line arguments without performing proper validation. The malicious data escapes that data plane by spawning new commands to be executed on the host.
  • Command Delimiters
    An attack of this type exploits a programs' vulnerabilities that allows an attacker's commands to be concatenated onto a legitimate command with the intent of targeting other resources such as the file system or database. The system that uses a filter or a blacklist input validation, as opposed to whitelist validation is vulnerable to an attacker who predicts delimiters (or combinations of delimiters) not present in the filter or blacklist. As with other injection attacks, the attacker uses the command delimiter payload as an entry point to tunnel through the application and activate additional attacks through SQL queries, shell commands, network scanning, and so on.
  • Exploiting Multiple Input Interpretation Layers
    An attacker supplies the target software with input data that contains sequences of special characters designed to bypass input validation logic. This exploit relies on the target making multiples passes over the input data and processing a "layer" of special characters with each pass. In this manner, the attacker can disguise input that would otherwise be rejected as invalid by concealing it with layers of special/escape characters that are stripped off by subsequent processing steps. The goal is to first discover cases where the input validation layer executes before one or more parsing layers. That is, user input may go through the following logic in an application: In such cases, the attacker will need to provide input that will pass through the input validator, but after passing through parser2, will be converted into something that the input validator was supposed to stop.
  • Argument Injection
    An attacker changes the behavior or state of a targeted application through injecting data or command syntax through the targets use of non-validated and non-filtered arguments of exposed services or methods.
  • OS Command Injection
    In this type of an attack, an adversary injects operating system commands into existing application functions. An application that uses untrusted input to build command strings is vulnerable. An adversary can leverage OS command injection in an application to elevate privileges, execute arbitrary commands and compromise the underlying operating system.
Access
VectorComplexityAuthentication
NETWORK LOW NONE
Impact
ConfidentialityIntegrityAvailability
COMPLETE COMPLETE COMPLETE
exploit-db via4
author Metasploit
date 2016-06-10
description IPFire - Bash Environment Variable Injection (Shellshock) (Metasploit)
file platforms/cgi/remote/39918.rb
id 39918
platform cgi
port 444
type remote
redhat via4
advisories
  • bugzilla
    id 1141597
    title CVE-2014-6271 bash: specially-crafted environment variables can be used to inject shell commands
    oval
    OR
    • AND
      • OR
        • comment Red Hat Enterprise Linux 6 Client is installed
          oval oval:com.redhat.rhsa:tst:20100842001
        • comment Red Hat Enterprise Linux 6 Server is installed
          oval oval:com.redhat.rhsa:tst:20100842002
        • comment Red Hat Enterprise Linux 6 Workstation is installed
          oval oval:com.redhat.rhsa:tst:20100842003
        • comment Red Hat Enterprise Linux 6 ComputeNode is installed
          oval oval:com.redhat.rhsa:tst:20100842004
      • OR
        • AND
          • comment bash is earlier than 0:4.1.2-15.el6_5.1
            oval oval:com.redhat.rhsa:tst:20141293005
          • comment bash is signed with Red Hat redhatrelease2 key
            oval oval:com.redhat.rhsa:tst:20141293006
        • AND
          • comment bash-doc is earlier than 0:4.1.2-15.el6_5.1
            oval oval:com.redhat.rhsa:tst:20141293007
          • comment bash-doc is signed with Red Hat redhatrelease2 key
            oval oval:com.redhat.rhsa:tst:20141293008
    • AND
      • comment Red Hat Enterprise Linux 5 is installed
        oval oval:com.redhat.rhsa:tst:20070055001
      • comment bash is earlier than 0:3.2-33.el5.1
        oval oval:com.redhat.rhsa:tst:20141293010
      • comment bash is signed with Red Hat redhatrelease key
        oval oval:com.redhat.rhsa:tst:20111073003
    • AND
      • OR
        • comment Red Hat Enterprise Linux 7 Client is installed
          oval oval:com.redhat.rhsa:tst:20140675001
        • comment Red Hat Enterprise Linux 7 Server is installed
          oval oval:com.redhat.rhsa:tst:20140675002
        • comment Red Hat Enterprise Linux 7 Workstation is installed
          oval oval:com.redhat.rhsa:tst:20140675003
        • comment Red Hat Enterprise Linux 7 ComputeNode is installed
          oval oval:com.redhat.rhsa:tst:20140675004
      • OR
        • AND
          • comment bash is earlier than 0:4.2.45-5.el7_0.2
            oval oval:com.redhat.rhsa:tst:20141293016
          • comment bash is signed with Red Hat redhatrelease2 key
            oval oval:com.redhat.rhsa:tst:20141293006
        • AND
          • comment bash-doc is earlier than 0:4.2.45-5.el7_0.2
            oval oval:com.redhat.rhsa:tst:20141293017
          • comment bash-doc is signed with Red Hat redhatrelease2 key
            oval oval:com.redhat.rhsa:tst:20141293008
    rhsa
    id RHSA-2014:1293
    released 2014-09-24
    severity Critical
    title RHSA-2014:1293: bash security update (Critical)
  • rhsa
    id RHSA-2014:1294
  • rhsa
    id RHSA-2014:1295
  • rhsa
    id RHSA-2014:1354
rpms
  • bash-0:4.1.2-15.el6_5.1
  • bash-doc-0:4.1.2-15.el6_5.1
  • bash-0:3.2-33.el5.1
  • bash-0:4.2.45-5.el7_0.2
  • bash-doc-0:4.2.45-5.el7_0.2
refmap via4
apple APPLE-SA-2014-10-16-1
bid 70103
bugtraq 20141001 NEW VMSA-2014-0010 - VMware product updates address critical Bash security vulnerabilities
cert TA14-268A
cert-vn VU#252743
cisco 20140926 GNU Bash Environmental Variable Command Injection Vulnerability
confirm
debian DSA-3032
fulldisc 20141001 FW: NEW VMSA-2014-0010 - VMware product updates address critical Bash security vulnerabilities
hp
  • HPSBGN03117
  • HPSBGN03138
  • HPSBGN03141
  • HPSBGN03142
  • HPSBGN03233
  • HPSBHF03119
  • HPSBHF03124
  • HPSBHF03125
  • HPSBHF03145
  • HPSBHF03146
  • HPSBMU03133
  • HPSBMU03143
  • HPSBMU03144
  • HPSBMU03165
  • HPSBMU03182
  • HPSBMU03217
  • HPSBMU03220
  • HPSBMU03245
  • HPSBMU03246
  • HPSBOV03228
  • HPSBST03122
  • HPSBST03129
  • HPSBST03131
  • HPSBST03148
  • HPSBST03154
  • HPSBST03155
  • HPSBST03157
  • HPSBST03181
  • HPSBST03195
  • HPSBST03196
  • HPSBST03265
  • SSRT101711
  • SSRT101739
  • SSRT101742
  • SSRT101816
  • SSRT101819
  • SSRT101827
  • SSRT101868
jvn JVN#55667175
jvndb JVNDB-2014-000126
mandriva MDVSA-2015:164
misc
secunia
  • 58200
  • 59272
  • 59737
  • 59907
  • 60024
  • 60034
  • 60044
  • 60055
  • 60063
  • 60193
  • 60325
  • 60433
  • 60947
  • 61065
  • 61128
  • 61129
  • 61188
  • 61283
  • 61287
  • 61291
  • 61312
  • 61313
  • 61328
  • 61442
  • 61471
  • 61485
  • 61503
  • 61542
  • 61547
  • 61550
  • 61552
  • 61565
  • 61603
  • 61633
  • 61641
  • 61643
  • 61654
  • 61676
  • 61700
  • 61703
  • 61711
  • 61715
  • 61780
  • 61816
  • 61855
  • 61857
  • 61873
  • 62228
  • 62312
  • 62343
suse
  • SUSE-SU-2014:1212
  • SUSE-SU-2014:1213
  • SUSE-SU-2014:1223
  • SUSE-SU-2014:1260
  • SUSE-SU-2014:1287
  • openSUSE-SU-2014:1226
  • openSUSE-SU-2014:1238
  • openSUSE-SU-2014:1254
  • openSUSE-SU-2014:1308
  • openSUSE-SU-2014:1310
ubuntu USN-2362-1
saint via4
  • bid 70103
    description ShellShock DHCP Server
    osvdb 112004
    title ssdhcp
    type client
  • bid 70103
    description Bash environment variable code injection over HTTP
    id shell_bash
    osvdb 112004
    title bash_shellshock_http
    type remote
  • bid 70103
    description Bash Environment Variable Handling Shell Command Injection Via CUPS
    id shell_bash
    osvdb 112004
    title bash_shellshock_cups
    type remote
vmware via4
description Bash libraries have been updated in multiple products to resolve multiple critical security issuesalso referred to as Shellshock.
id VMSA-2014-0010
last_updated 2014-10-17T00:00:00
published 2014-09-30T00:00:00
title Bash update for multiple products
workaround None
Last major update 06-01-2017 - 22:00
Published 24-09-2014 - 14:48
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