A vulnerability in the AnyConnect SSL VPN feature of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to an implementation error within the SSL/TLS session handling process that can prevent the release of a session handler under specific conditions. An attacker could exploit this vulnerability by sending crafted SSL/TLS traffic to an affected device, increasing the probability of session handler leaks. A successful exploit could allow the attacker to eventually deplete the available session handler pool, preventing new sessions from being established and causing a DoS condition.
The CVSS score for this vulnerability is 6.8, indicating a medium severity level, primarily due to the potential for high availability impact. Organizations utilizing affected Cisco products should be aware of the risks associated with this vulnerability and take necessary actions to secure their environments.
Risk to organizations includes the possibility of service disruption, which could affect business operations and customer trust. Given the nature of this vulnerability and its potential impact, organizations should prioritize patching immediately.
Currently, there are no known exploits or public proofs of concept available for this vulnerability. However, organizations should remain vigilant and monitor their systems for any unusual activity.
Vulnerability Details
This vulnerability allows an unauthenticated remote attacker to send crafted SSL/TLS traffic to an affected device, potentially leading to a denial of service condition. The CVSS score, as noted, varies between 6.8 and 8.6 based on different metrics, with the latter reflecting a high severity classification. The availability impact is particularly concerning, as it can prevent new sessions from being established.
Technical Analysis
The root cause of this vulnerability stems from an implementation error in the SSL/TLS session handling process, which can lead to session handler leaks. The attack vector is through the network, necessitating no user interaction and requiring no privileges, thus making it easier for attackers to exploit.
The attack complexity is high, indicating that an attacker must have a certain level of skill to successfully exploit this vulnerability. The impacts on confidentiality and integrity are none, but the availability impact is rated as high, emphasizing the significant risk posed to operational continuity.
Risk & Impact Analysis
Organizations using Cisco ASA or FTD Software should be aware of the potential service disruption this vulnerability poses. Given its ability to prevent the establishment of new sessions, the blast radius could be significant, potentially affecting any users attempting to access services through the affected devices.
The urgency for remediation is moderate, as organizations should address this vulnerability in their priority patch cycle to avoid potential exploitation and service outages.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
All versions of Cisco Adaptive Security Appliance Software and Cisco Firepower Threat Defense Software prior to the latest vendor patch are affected. Specific vulnerable versions include, but are not limited to, Firepower Threat Defense versions 7.0.0 to 7.3.1.1 and Adaptive Security Appliance Software versions 9.16.1 to 9.19.1.
Mitigation & Remediation
Organizations should apply the latest patches provided by Cisco to remediate this vulnerability. For those unable to immediately implement a patch, it is advisable to implement network segmentation to limit exposure to potentially malicious SSL/TLS traffic. Regular monitoring of network traffic for anomalies may also help in identifying potential exploitation attempts.
Further, organizations may consider engaging in penetration testing to validate the effectiveness of their security measures.
Detection Guidance
Organizations should monitor logs for unusual SSL/TLS traffic patterns, which could indicate attempts to exploit this vulnerability. Behavioral anomalies in session handling may also serve as indicators of potential exploitation.
AppSecure Threat Intelligence Insight
The long-term significance of this vulnerability lies in its potential impact on service availability and the need for organizations to remain vigilant about SSL/TLS configurations. This incident highlights the importance of regular security assessments to uncover vulnerabilities before they can be exploited.
Security teams are advised to stay informed about emerging threats and continuously improve their security postures. Engaging in regular training and awareness programs can significantly enhance an organization's ability to respond to such vulnerabilities.
For more information on securing your infrastructure, consider reviewing our vulnerability management program and best practices.
Consider also engaging in penetration testing methodology to ensure security measures are effective.
Lastly, reviewing your approach to cloud security assessments can provide additional insights into potential vulnerabilities.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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