Atomicorp WAF Rule 330701

Rule Summary

• Rule ID: 330701
• Status: Active
• Alert message: Atomicorp.com WAF Rules: CVE-2014-6271 Bash Attack
• Observed CWEs: CWE-78 (1)
• Revision: 3
• Rule severity: Alert (1)
• Phase: 1 (request headers)
• Request surfaces: Request headers, Request argument names, Request arguments, JSON request data, SOAP request data
• Rule action: deny
• HTTP status: 403
• Logging: log, auditlog

Description

This rules detects when a potential attack is made against a web application, such as a CGI application, to take advantage of the bash shell CVE-2014-6271 vulnerability. The vulnerability allows remote command execution against the system. If you are not sure if you have patched bash to prevent this attack, do not disable this rule.

Troubleshooting

False Positives

It is not recommended that you disable this rule if you have a false positive. If you believe this is a false positive, please report this to our security team to determine if this is a legitimate case, or if its clever attack on your system. Instructions to report false positives are detailed on the Reporting False Positives wiki page. If it is a false positive, we will fix the issue in the rules and get a release out to you promptly.

Tuning Guidance

Please see the Tuning the Atomicorp WAF Rules page for basic information if you wish to tune, or disable this rule.

CVEs Referenced by This Rule

The current ModSecurity rule metadata explicitly names the following CVEs. These references explain the rule author’s association; they do not claim that the rule is limited to these vulnerabilities or that this is an exhaustive coverage list.

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 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.

• Association: The rule references CVE-2014-6271 in its alert message.
• CVE Record (opens in a new tab)
• NVD (opens in a new tab)

Selected Related CVEs

This is a selected list of documented research observations, not an exhaustive coverage matrix. Absence of a CVE does not imply absence of protection.

Observed CWEs

These CWEs are recorded on published CVEs in the selected observations associated with this rule. They are observational relationships, not a claim that the rule universally blocks every vulnerability assigned to a CWE.

Documentation Source

• Original wiki page: WAF 330701
• Source revision: 5134
• Source revision date: 2014-09-24