CVE-2021-41282 is a high-severity vulnerability affecting pfSense version 2.5.2, specifically in the diag_routes.php script. This vulnerability allows sed data injection, where authenticated users may inadvertently execute malicious commands by exploiting how data is retrieved and processed. The issue arises from the usage of the netstat utility to gather routing information, which is then parsed using sed. Although protective measures like escapeshellarg are implemented, the vulnerability remains exploitable, allowing an attacker to inject sed-specific code and write arbitrary files.
The CVSS score for this vulnerability is 8.8, categorizing it as high severity. This score indicates a significant risk to organizations, particularly those utilizing pfSense in their network infrastructure. The attack vector is network-based, with a low attack complexity, meaning that exploitation does not require advanced skills. Additionally, the impact on confidentiality, integrity, and availability is assessed as high, emphasizing the critical nature of this vulnerability.
Given the high severity and potential impact, organizations using pfSense should prioritize patching to prevent exploitation. The urgency for remediation is heightened by the network attack vector and low complexity of the exploit. It is crucial for security teams to assess their systems and apply the necessary updates promptly to mitigate the risk associated with this vulnerability.
As of now, there is no known public exploit available, and the vulnerability has not been included in the Known Exploited Vulnerabilities (KEV) catalog. Nevertheless, organizations should remain vigilant as the potential for exploitation through sed data injection poses a severe threat that must be addressed immediately.
Vulnerability Details
The vulnerability is classified as a command injection, specifically CWE-74. It allows attackers to manipulate command execution through the sed utility in pfSense 2.5.2. The official description notes that although protective mechanisms are in place, they do not fully mitigate the risks associated with this vulnerability.
The affected product is pfSense, version 2.5.2, with the vulnerability first published on March 1, 2022. The implications of this vulnerability are significant as it could lead to unauthorized access and manipulation of sensitive data, resulting in severe operational disruptions.
Technical Analysis
The root cause of the vulnerability lies in the way pfSense processes routing data. By executing the netstat utility and parsing its output via sed, the application inadvertently allows crafted input to manipulate command execution. The attack vector is purely network-based, and the attack complexity is low, meaning that even individuals with basic skills can exploit it if they have authenticated access.
In terms of privileges required, the vulnerability can be exploited with low privileges, as authenticated users are the ones intended to access the routing information. User interaction is not required for exploitation, making it even more critical. The potential impact on confidentiality, integrity, and availability is high, meaning successful exploitation can lead to significant data breaches and service interruptions.
Risk & Impact Analysis
Risk to organizations includes potential data breaches and unauthorized access to sensitive routing information. Given the critical nature of network infrastructure, a successful exploit could lead to service outages and compromise the integrity of the firewall. As the vulnerability allows for arbitrary file writes, attackers could leverage this to escalate their privileges further or install backdoors for persistent access.
The urgency for remediation is high considering the CVSS score of 8.8 and the potential for widespread impact. Organizations should prioritize patching as soon as updates are available to safeguard their systems. The blast radius could be significant, affecting not only the compromised system but also the broader network infrastructure.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
The only affected version is pfSense 2.5.2. Organizations should note that all versions prior to the vendor patch are at risk. It is crucial to update to the latest version as soon as possible to mitigate this vulnerability.
Mitigation & Remediation
Organizations should apply the latest patches provided by pfSense to remediate this vulnerability effectively. For those unable to immediately patch, consider implementing workarounds such as restricting access to the diag_routes.php script to only trusted users. Additionally, configuration hardening is recommended to minimize attack surface.
Monitoring network traffic for unusual behavior around the pfSense firewall can help detect potential exploitation attempts. Regular security audits and adherence to best practices in network security are also advised.
For more comprehensive testing, organizations may consider utilizing penetration testing services to identify vulnerabilities like CVE-2021-41282.
Detection Guidance
To detect potential exploitation of this vulnerability, organizations should monitor logs for any unusual commands executed within the pfSense environment. Behavioral anomalies such as unexpected file creations or modifications should be flagged for review. Additionally, establishing network signatures that identify unauthorized access attempts can aid in early detection.
AppSecure Threat Intelligence Insight
The long-term significance of this vulnerability lies in its ability to exploit fundamental weaknesses in command execution handling. Organizations must learn from this incident and reinforce their security measures against similar vulnerabilities in the future. Continuous monitoring and timely updates are crucial to maintaining a robust security posture.
This vulnerability highlights the importance of regular security assessments and adopting a proactive stance on security. Security teams should prioritize training and awareness to recognize and respond to such vulnerabilities swiftly.
For further insights on vulnerability management, organizations can refer to our guide on vulnerability management programs and explore best practices for mitigating risks effectively.
Organizations should also stay informed about security trends and updates to enhance their incident response strategies and reduce the likelihood of similar vulnerabilities occurring.
For comprehensive insights on penetration testing and security assessments, organizations can explore our resources on penetration testing methodologies.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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