Think you have a false positive on this rule?

Sid 1-32335

Message

OS-OTHER Bash CGI environment variable injection attempt

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 modcgi and modcgid 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.

Impact

CVSS base score 10.0 CVSS impact score 10.0 CVSS exploitability score 10.0 confidentialityImpact COMPLETE integrityImpact COMPLETE availabilityImpact COMPLETE

CVE-2014-6271:

CVSS base score 10.0

CVSS impact score 10.0

CVSS exploitability score 10.0

Confidentiality Impact COMPLETE

Integrity Impact COMPLETE

Availability Impact COMPLETE

CVE-2014-6277:

CVSS base score 10.0

CVSS impact score 10.0

CVSS exploitability score 10.0

Confidentiality Impact COMPLETE

Integrity Impact COMPLETE

Availability Impact COMPLETE

CVE-2014-6278:

CVSS base score 10.0

CVSS impact score 10.0

CVSS exploitability score 10.0

Confidentiality Impact COMPLETE

Integrity Impact COMPLETE

Availability Impact COMPLETE

CVE-2014-7169:

CVSS base score 10.0

CVSS impact score 10.0

CVSS exploitability score 10.0

Confidentiality Impact COMPLETE

Integrity Impact COMPLETE

Availability Impact COMPLETE

Detailed information

CVE-2014-6271: 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 modcgi and modcgid 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.

CVE-2014-6277: GNU Bash through 4.3 bash43-026 does not properly parse function definitions in the values of environment variables, which allows remote attackers to execute arbitrary code or cause a denial of service (uninitialized memory access, and untrusted-pointer read and write operations) via a crafted environment, as demonstrated by vectors involving the ForceCommand feature in OpenSSH sshd, the modcgi and modcgid 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. NOTE: this vulnerability exists because of an incomplete fix for CVE-2014-6271 and CVE-2014-7169.

CVE-2014-6278: GNU Bash through 4.3 bash43-026 does not properly parse function definitions in the values of environment variables, which allows remote attackers to execute arbitrary commands via a crafted environment, as demonstrated by vectors involving the ForceCommand feature in OpenSSH sshd, the modcgi and modcgid 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. NOTE: this vulnerability exists because of an incomplete fix for CVE-2014-6271, CVE-2014-7169, and CVE-2014-6277.

CVE-2014-7169: GNU Bash through 4.3 bash43-025 processes trailing strings after certain malformed function definitions in the values of environment variables, which allows remote attackers to write to files or possibly have unknown other impact via a crafted environment, as demonstrated by vectors involving the ForceCommand feature in OpenSSH sshd, the modcgi and modcgid 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. NOTE: this vulnerability exists because of an incomplete fix for CVE-2014-6271.

Affected systems

  • gnu bash 1.14.0
  • gnu bash 1.14.1
  • gnu bash 1.14.2
  • gnu bash 1.14.3
  • gnu bash 1.14.4
  • gnu bash 1.14.5
  • gnu bash 1.14.6
  • gnu bash 1.14.7
  • gnu bash 2.0
  • gnu bash 2.01
  • gnu bash 2.01.1
  • gnu bash 2.02
  • gnu bash 2.02.1
  • gnu bash 2.03
  • gnu bash 2.04
  • gnu bash 2.05
  • gnu bash 3.0
  • gnu bash 3.0.16
  • gnu bash 3.1
  • gnu bash 3.2
  • gnu bash 3.2.48
  • gnu bash 4.0
  • gnu bash 4.1
  • gnu bash 4.2
  • gnu bash 4.3

Ease of attack

CVE-2014-6271:

Access Vector NETWORK

Access Complexity LOW

Authentication NONE

CVE-2014-6277:

Access Vector NETWORK

Access Complexity LOW

Authentication NONE

CVE-2014-6278:

Access Vector NETWORK

Access Complexity LOW

Authentication NONE

CVE-2014-7169:

Access Vector NETWORK

Access Complexity LOW

Authentication NONE

False positives

None known

False negatives

None known

Corrective action

Upgrade to the latest non-affected version of the software.

Apply the appropriate vendor supplied patches.

Contributors

  • Talos research team.
  • This document was generated from data supplied by the national vulnerability database, a product of the national institute of standards and technology.
  • For more information see nvd.

Additional References