A vulnerability in the LUA interpreter of the Remote Access SSL VPN feature of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Secure Firewall Threat Defense (FTD) Software could allow an authenticated, remote attacker with a valid VPN connection to cause the device to reload unexpectedly, resulting in a denial of service (DoS) condition. This does not affect the management or MUS interfaces. This vulnerability is due to trusting user input without validation in the LUA interpreter.
An attacker could exploit this vulnerability by sending crafted HTTP packets to the Remote Access SSL VPN server. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition. With a CVSS score of 7.7, this vulnerability is classified as high severity. Organizations using affected Cisco products should prioritize patching immediately.
Risk to organizations includes potential service disruption and loss of availability, which can significantly affect business operations. As the vulnerability is currently undergoing analysis, organizations should remain vigilant and monitor for updates from Cisco regarding any patches or mitigations.
This vulnerability does not have confirmed exploits available at this time, but the nature of the issue suggests that it could be targeted by attackers seeking to disrupt services. Therefore, organizations should address this vulnerability in their priority patch cycle.
Vulnerability Details
The vulnerability described allows an attacker to exploit the LUA interpreter within the Remote Access SSL VPN functionality of Cisco Secure Firewall ASA and FTD Software. The specific vulnerability is classified under CWE-120, which refers to buffer copy without checking size of input. This could lead to a situation where the device becomes unresponsive due to the unexpected reload.
The CVSS vector string associated with this vulnerability is CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H, indicating that the attack vector is network-based, the attack complexity is low, and it requires low privileges with no user interaction required.
Technical Analysis
The root cause of this vulnerability lies in the improper validation of user input within the LUA interpreter. Attackers may leverage this flaw by sending specially crafted HTTP packets to the vulnerable server. This exploitation can lead to a denial of service condition as the device may reload unexpectedly.
The attack vector is network-based, meaning that attackers can exploit this vulnerability remotely without requiring physical access to the device. The attack complexity is classified as low, suggesting that the exploitation does not require advanced skills or knowledge.
Furthermore, the vulnerability requires low privileges, as an authenticated user with a valid VPN connection can initiate the attack. There is no user interaction required, which increases the likelihood of successful exploitation.
Risk & Impact Analysis
Real-world deployment risk associated with this vulnerability is significant, as the potential denial of service can disrupt critical business operations relying on VPN access. Given that this vulnerability allows for a remote attacker to cause device reboots, the blast radius could affect multiple users and services connected to the VPN.
Organizations should assess the urgency of addressing this vulnerability based on its CVSS score of 7.7. This high severity rating necessitates immediate attention to mitigate potential risks. Security teams should consider this vulnerability's implications in their risk management strategies.
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
As of now, there are no specific version ranges provided for this vulnerability. Organizations using Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense Software should assume that all versions prior to any forthcoming vendor patch are affected.
Mitigation & Remediation
Organizations should prioritize patching immediately and monitor for updates from Cisco regarding the resolution of this vulnerability. Implementing configuration hardening and access controls can also mitigate risks. For further assistance, organizations may consider engaging in penetration testing to validate security posture.
Detection Guidance
Organizations should monitor logs for indicators of unusual access patterns or attempts to exploit this vulnerability. Behavioral anomalies and network signatures associated with the Remote Access SSL VPN functionality should be closely scrutinized. Additionally, changes in system performance may indicate attempts to exploit the vulnerability.
AppSecure Threat Intelligence Insight
The long-term significance of this vulnerability lies in the reliance on LUA interpreters in various applications. This incident highlights the need for robust input validation and the dangers of trusting user input. Security teams should learn from this event to strengthen their defenses against similar vulnerabilities.
This incident also reflects a broader trend in vulnerabilities arising from insufficient input validation. Organizations should implement comprehensive security testing practices, such as penetration testing methodology, to proactively identify and remediate such weaknesses.
Security teams must also consider the implications of such vulnerabilities for their incident response plans. Developing a thorough understanding of how to respond to potential DoS attacks is critical. This includes engaging in proactive measures and ensuring that incident response teams are equipped to handle such situations effectively.
For organizations concerned about their security posture, engaging in red teaming services could provide valuable insights into potential vulnerabilities in their systems.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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