# CVE-2022-20927: Denial of service in Cisco Adaptive Security Appliance (ASA) Software

> An authenticated remote attacker can cause a denial of service on Cisco ASA and FTD devices by forcing connections to malicious SSL/TLS servers.

- **Severity:** High 7.7 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 10 Nov 2022
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-4g76-357g-vr49

## What is CVE-2022-20927?

CVE-2022-20927 is a high-severity denial of service vulnerability in Cisco Adaptive Security Appliance Software, published on 10 Nov 2022. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A vulnerability in the SSL/TLS client of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an authenticated, remote attacker to cause a denial of service (DoS) condition on an affected device.

 This vulnerability is due to improper memory management when a device initiates SSL/TLS connections. An attacker could exploit this vulnerability by ensuring that the device will connect to an SSL/TLS server that is using specific encryption parameters. A successful exploit could allow the attacker to cause the affected device to unexpectedly reload, resulting in a DoS condition.

Weakness: CWE-120 (Buffer Copy without Checking Size of Input)

## Which versions are affected by CVE-2022-20927?

It affects 3 products.


Products: Cisco Adaptive Security Appliance Software, Cisco Firepower Services Software for Asa, Cisco Secure Firewall Threat Defense.

## How do I fix CVE-2022-20927?

No fix has been published for CVE-2022-20927 yet. Limit exposure of the affected software until one is available.

## Is CVE-2022-20927 being exploited?

There is no known exploitation of CVE-2022-20927 in the wild and no public exploit code.

## 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-2022-20927 and fix it if it is affected.

What it is: CVE-2022-20927 is a high-severity denial of service vulnerability in Cisco Adaptive Security Appliance Software, published on 10 Nov 2022. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2022-20927 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-2022-20927/ (Markdown: https://insights.sbomify.com/CVE-2022-20927/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-20927
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-20927
- OSV: https://osv.dev/vulnerability/CVE-2022-20927

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From sbomify Insights: https://insights.sbomify.com/CVE-2022-20927/
Summaries are generated and may contain mistakes; the official description above is the record.