CVE-2022-20866

HIGH

Cisco ASA 9.16.0-9.16.3.19 & FTD 7.0.0-7.0.4 - Unauthenticated RSA Private Key Retrieval via Lenstra Attack

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 1 public exploit for CVE-2022-20866. PoCs published by CiscoPSIRT.

AI-analyzed exploit summary This repository provides a Python-based tool to check RSA keys exported from Cisco ASA or FTD devices for susceptibility to CVE-2022-20866, a vulnerability that could allow an attacker to retrieve the RSA private key via a Lenstra side-channel attack. The tool analyzes PKCS12 files for malformed or vulnerable keys.

Description

A vulnerability in the handling of RSA keys on devices running Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to retrieve an RSA private key. This vulnerability is due to a logic error when the RSA key is stored in memory on a hardware platform that performs hardware-based cryptography. An attacker could exploit this vulnerability by using a Lenstra side-channel attack against the targeted device. A successful exploit could allow the attacker to retrieve the RSA private key. The following conditions may be observed on an affected device: This vulnerability will apply to approximately 5 percent of the RSA keys on a device that is running a vulnerable release of Cisco ASA Software or Cisco FTD Software; not all RSA keys are expected to be affected due to mathematical calculations applied to the RSA key. The RSA key could be valid but have specific characteristics that make it vulnerable to the potential leak of the RSA private key. If an attacker obtains the RSA private key, they could use the key to impersonate a device that is running Cisco ASA Software or Cisco FTD Software or to decrypt the device traffic. See the Indicators of Compromise section for more information on the detection of this type of RSA key. The RSA key could be malformed and invalid. A malformed RSA key is not functional, and a TLS client connection to a device that is running Cisco ASA Software or Cisco FTD Software that uses the malformed RSA key will result in a TLS signature failure, which means a vulnerable software release created an invalid RSA signature that failed verification. If an attacker obtains the RSA private key, they could use the key to impersonate a device that is running Cisco ASA Software or Cisco FTD Software or to decrypt the device traffic.

Exploits (1)

nomisec SCANNER 7 stars
by CiscoPSIRT · poc
https://github.com/CiscoPSIRT/CVE-2022-20866

This repository provides a Python-based tool to check RSA keys exported from Cisco ASA or FTD devices for susceptibility to CVE-2022-20866, a vulnerability that could allow an attacker to retrieve the RSA private key via a Lenstra side-channel attack. The tool analyzes PKCS12 files for malformed or vulnerable keys.

Classification
Scanner 100%
Attack Type
Info Leak
Complexity
Moderate
Reliability
Reliable
Target: Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software
No auth needed
Prerequisites: PKCS12 file exported from the target device · OpenSSL command line tool
devstral-2 · analyzed Feb 16, 2026 Full analysis →

References (1)

Core 1

Scores

CVSS v3 7.4
EPSS 0.1665
EPSS Percentile 96.6%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact total

Details

CWE
CWE-203
Status published
Products (2)
cisco/adaptive_security_appliance_software 9.16.0 - 9.16.3.19
cisco/firepower_threat_defense 7.0.0 - 7.0.4
Published Aug 10, 2022
Tracked Since Feb 18, 2026