This article discusses the discovery of a high severity flaw in Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software. Tracked as CVE-2022-20866, this vulnerability enables remote attackers to retrieve RSA private keys. The flaw is attributed to a logic error in RSA key storage on a hardware-based cryptography platform and can be exploited using the Lenstra side-channel attack. Notably, several Cisco products are affected, including the ASA 5506-X, Firepower 1000 Series, and Secure Firewall 3100. Approximately 5% of RSA keys on vulnerable software releases are impacted, although the mathematical calculations involved mean that not all RSA keys are affected. Consequently, the presence of malformed RSA keys may result in TLS signature failure, potentially allowing attackers to impersonate or decrypt device traffic. Cisco has addressed the issue by releasing fixed versions for the affected software releases, and the flaw was initially reported by researchers from the University of California San Diego and the University of Colorado Boulder. The vulnerability presents a risk of RSA private key leakage to malicious actors.
Key Takeaways
- Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software have a high severity flaw (CVE-2022-20866) that allows remote attackers to retrieve RSA private keys.
- This flaw is a result of a logic error in RSA key storage on hardware-based cryptography platforms and can be exploited through Lenstra side-channel attack.
- Around 5% of RSA keys on vulnerable software releases are impacted, and not all RSA keys are affected due to mathematical calculations.
- The fixed releases for ASA Software are 9.16 and later, while for FTD Software, the fixed releases are 7.0.0 and later.
Vulnerability Description
The vulnerability description of the high severity flaw in Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software, tracked as CVE-2022-20866, highlights that it allows remote attackers to retrieve RSA private keys due to a logic error in RSA key storage on the hardware-based cryptography platform, which can be exploited through the Lenstra side-channel attack. This vulnerability has significant implications for network security as it enables attackers to potentially impersonate or decrypt device traffic. It is crucial for organizations to implement countermeasures and mitigation strategies to protect their RSA keys. This may include updating the affected software releases to the fixed versions provided by Cisco, such as 9.16.3.19, 9.17, 9.17.1.13, 9.18, 9.18.2 for ASA Software, and 7.0.4, 7.1.0, 7.2.0, 7.2.0.1 for FTD Software. Additionally, monitoring and auditing RSA keys for any signs of vulnerability or compromise is essential to ensure network security.
Affected Products
Affected products include ASA 5506-X with FirePOWER Services, ASA 5506H-X with FirePOWER Services, ASA 5506W-X with FirePOWER Services, ASA 5508-X with FirePOWER Services, ASA 5516-X with FirePOWER Services, Firepower 1000 Series Next-Generation Firewall, Firepower 2100 Series Security Appliances, Firepower 4100 Series Security Appliances, Firepower 9300 Series Security Appliances, and Secure Firewall 3100. The vulnerability described in the previous subtopic poses a significant impact on network security. Attackers can exploit this flaw to retrieve RSA private keys remotely, which could lead to impersonation or decryption of device traffic. To mitigate the risk, Cisco has released fixed software versions for the affected devices. Network administrators should promptly update their systems to the fixed releases mentioned earlier. Regular monitoring of the Cisco Security Advisory and applying necessary patches is crucial to ensure the security of the network infrastructure.
Conditions Observed on Affected Devices
Observations on the affected devices reveal that a small percentage of RSA keys are impacted by the vulnerability, with only specific characteristics resulting in TLS signature failure. The vulnerability in the Cisco software allows attackers to retrieve the RSA private key remotely through a logic error in RSA key storage on the hardware-based cryptography platform. While not all RSA keys are affected due to mathematical calculations, the vulnerable keys may be valid but possess certain characteristics. The presence of malformed RSA keys can lead to the failure of TLS signatures. This has significant implications as attackers can potentially impersonate or decrypt device traffic, compromising the security and integrity of the affected devices. It is crucial for organizations to apply the fixed releases provided by Cisco to mitigate the impact on device traffic and prevent the leakage of RSA private keys to malicious actors.
