# CVE-2022-20866: Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software RSA Private Key Leak Vulnerability > Remote attackers can retrieve RSA private keys via side-channel attacks, enabling device impersonation and traffic decryption on Cisco ASA and FTD devices. - **Severity:** High 7.4 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N`) - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** No - **Published:** 10 Aug 2022 - **Updated:** 1 Nov 2024 - **Also known as:** GHSA-96q7-c2w2-93p8 ## What is CVE-2022-20866? CVE-2022-20866 is a high-severity vulnerability in Cisco Adaptive Security Appliance Software, published on 10 Aug 2022. An attacker can exploit it over the internet without logging in, with no action from the victim. ### Official 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. Weakness: CWE-203 (Observable Discrepancy) ## Which versions are affected by CVE-2022-20866? It affects 2 products. Products: Cisco Adaptive Security Appliance Software, Cisco Secure Firewall Threat Defense. ## How do I fix CVE-2022-20866? No fix has been published for CVE-2022-20866 yet. Limit exposure of the affected software until one is available. ## Is CVE-2022-20866 being exploited? There is no known exploitation of CVE-2022-20866 in the wild and no public exploit code. Public exploit code: - RSA Key Checker for CVE-2022-20866 (github_poc): https://github.com/CiscoPSIRT/CVE-2022-20866 ## Other vulnerabilities in Cisco Adaptive Security Appliance Software - [CVE-2025-20333](https://insights.sbomify.com/CVE-2025-20333/): Cisco Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD) Buffer Overflow (critical 9.9, exploited in the wild) - [CVE-2016-6366](https://insights.sbomify.com/CVE-2016-6366/): Cisco Adaptive Security Appliance (ASA) SNMP Buffer Overflow (high 8.8, exploited in the wild) - [CVE-2026-20349](https://insights.sbomify.com/CVE-2026-20349/): Cisco Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD) Heap Inspection (high 8.6, exploited in the wild) - [CVE-2024-20353](https://insights.sbomify.com/CVE-2024-20353/): Cisco ASA and FTD Denial of Service (high 8.6, exploited in the wild) - [CVE-2016-6367](https://insights.sbomify.com/CVE-2016-6367/): Cisco Adaptive Security Appliance (ASA) CLI Remote Code Execution (high 7.8, exploited in the wild) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2022-20866 and fix it if it is affected. What it is: CVE-2022-20866 is a high-severity vulnerability in Cisco Adaptive Security Appliance Software, published on 10 Aug 2022. An attacker can exploit it over the internet without logging in, with no action from the victim. Exploitation: There is no known exploitation of CVE-2022-20866 in the wild and no public exploit code. Affected product: Cisco Adaptive Security Appliance Software. No package-level version data is available, so check the vendor advisory linked from the reference page. Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2022-20866/ (Markdown: https://insights.sbomify.com/CVE-2022-20866/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2022-20866 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-20866 - OSV: https://osv.dev/vulnerability/CVE-2022-20866 --- From sbomify Insights: https://insights.sbomify.com/CVE-2022-20866/ Summaries are generated and may contain mistakes; the official description above is the record.