GNU Bash OS Command Injection Vulnerability - Active in CISA KEV catalog.
Description
GNU Bash OS Command Injection Vulnerability - Active in CISA KEV catalog.
AI Analyst Comment
Remediation
FEDERAL DEADLINE: October 22, 2025 (21 days). Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. FEDERAL DEADLINE: October 22, 2025 (21 days). Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
CISA KEV Details
Deadline: October 22, 2025
Required Action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Description Summary:
GNU Bash fails to properly parse function definitions in environment variables, allowing remote attackers to execute arbitrary commands via crafted environment input.
Executive Summary:
This critical vulnerability, part of the Shellshock family, allows unauthenticated remote attackers to execute arbitrary system commands, and it is confirmed to be actively exploited in the wild.
Vulnerability Details
CVE-ID: CVE-2014-6278
Affected Software: GNU Bash
Affected Versions: GNU Bash through 4.3 bash43-026 (versions 1.14 through 4.3)
Vulnerability: The vulnerability stems from an incomplete fix for previous Shellshock flaws, where the shell improperly handles function definitions within environment variables. An unauthenticated attacker can exploit this when Bash is invoked across a privilege boundary, such as through Apache HTTP Server CGI scripts, OpenSSH, or specific DHCP client configurations.
Business Impact
Successful exploitation provides an attacker with remote code execution capabilities on the host system, potentially leading to a complete system compromise. Given its CVSS score of 9.5, this flaw poses an extreme risk to confidentiality, integrity, and availability, as it can be used to install persistent backdoors, exfiltrate sensitive data, or deploy botnet malware. The inclusion of this vulnerability in the CISA Known Exploited Vulnerabilities (KEV) catalog highlights its ongoing utility to threat actors for widespread system exploitation.
Remediation Plan
Immediate Action: Update the Bash package to bash43-027 or later, or apply the specific security patches provided by your OS vendor, such as Red Hat's RHSA-2014:1306 or Ubuntu's updated packages for 12.04 LTS and 10.04 LTS.
Proactive Monitoring: Monitor system logs for suspicious process spawning, particularly those originating from web server (CGI) or SSH processes, and scan for anomalous outbound network traffic indicative of botnet activity.
Compensating Controls: Implement a Web Application Firewall (WAF) to filter out requests containing malicious function definitions in headers or environment variables, and restrict shell access where possible.
Exploitation Status
Public Exploit Available: Yes, a Metasploit module and ExploitDB entry exist.
Analyst Notes: This vulnerability is confirmed to be actively exploited in the wild as of October 2, 2025. The flaw is highly dangerous due to its ease of remote exploitation and the prevalence of vulnerable software in legacy infrastructure.
Analyst Recommendation
Due to the critical nature of this vulnerability and its history of active exploitation, immediate patching is mandatory for all affected systems. Organizations should prioritize identifying and updating all instances of GNU Bash to the latest version to prevent unauthorized remote command execution and potential system takeover.