CVE-2021-27104 is a critical vulnerability in Accellion's File Transfer Appliance (FTA), where OS command execution can be triggered via a crafted POST request to various administrative endpoints. This flaw affects FTA versions 9_12_370 and earlier, necessitating an upgrade to version FTA_9_12_380 or later to remediate the issue. With a CVSS score of 9.8, this vulnerability poses a significant risk to organizations that utilize affected versions.
The vulnerability allows attackers to execute arbitrary commands, potentially compromising system integrity and confidentiality. Given its critical nature and ease of exploitation, organizations should prioritize patching immediately to prevent unauthorized access and data breaches.
Currently, there is no public exploit confirmed, but the vulnerability is included in the Known Exploited Vulnerabilities (KEV) catalog, indicating its relevance in the threat landscape. Organizations utilizing Accellion FTA should assess their deployments and take appropriate actions to mitigate associated risks.
Timely remediation is critical, as the potential impact of exploitation includes loss of data confidentiality, integrity, and availability. Organizations are advised to remain vigilant and review their security posture concerning this vulnerability.
Vulnerability Details
Accellion FTA 9_12_370 and earlier is affected by OS command execution via a crafted POST request to various admin endpoints. The fixed version is FTA_9_12_380 and later. This vulnerability is classified as CWE-78 (OS Command Injection), which indicates improper input validation leading to the execution of shell commands.
The CVSS score assigned to this vulnerability is 9.8, indicating a critical severity level. The attack vector is NETWORK, with low complexity and no privileges required for exploitation. The potential impacts include high confidentiality, integrity, and availability loss.
Technical Analysis
The root cause of CVE-2021-27104 lies in insufficient input validation for commands executed via POST requests. Attackers can exploit this vulnerability by manipulating the request parameters to execute arbitrary commands on the server.
The attack vector is network-based, allowing remote access without requiring any privileges or user interaction. The attack complexity is low, making it accessible for malicious actors. The confidentiality, integrity, and availability impacts are all rated high, indicating severe consequences if exploited.
Risk & Impact Analysis
Organizations utilizing Accellion FTA are at significant risk due to the potential for data breaches and unauthorized access. The widespread nature of this vulnerability and its critical severity level highlight the urgency for organizations to act.
Given its inclusion in the KEV catalog and the known ransomware campaign use, organizations must address this vulnerability in their patching cycles. The blast radius of such exploitation could be extensive, affecting customer data and organizational reputation.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | Yes |
Ransomware Use | Yes |
Affected Versions
Affected versions include Accellion FTA versions 9_12_370 and earlier. Organizations utilizing these versions should upgrade to FTA_9_12_380 or later to mitigate risks.
Mitigation & Remediation
Organizations must apply the vendor's patch for FTA to version FTA_9_12_380 or later. If immediate patching is not possible, implement network segmentation to limit access to the affected systems and monitor for unusual activity.
Additionally, organizations should conduct regular security assessments, including penetration testing, to ensure their systems remain secure against potential exploitation.
Detection Guidance
Organizations should monitor logs for suspicious POST requests to administrative endpoints of the Accellion FTA. Behavioral anomalies, such as unusual command executions or access patterns, should be flagged for immediate investigation.
AppSecure Threat Intelligence Insight
The long-term significance of CVE-2021-27104 reflects a broader trend in the landscape of web applications where command injection vulnerabilities continue to be prevalent. Organizations must not only remediate this specific vulnerability but also review their overall security posture against similar threats.
Security teams should invest in training and awareness programs to recognize and mitigate command injection vulnerabilities. Additionally, adopting best practices in secure coding and application security assessments will enhance resilience against such exploits.
For further reading on best practices, organizations can refer to our penetration testing methodology and vulnerability management program design to proactively address vulnerabilities.
Finally, it's essential for organizations to stay informed about emerging threats and to continuously enhance their security frameworks to adapt to the evolving landscape.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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