Vulnerability identifier: #VU26756

Vulnerability risk: Medium

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-1730

CWE-ID: CWE-399

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
libssh
Universal components / Libraries / Libraries used by multiple products

Vendor: libssh

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to improper resource management while cleaning the AES-CTR ciphers when closing the connection. A remote attacker can initiate a connection to the client and server that supports AES-CTR ciphers and close the connection before ciphers are initialized, triggering a denial of service condition (service crash). The vulnerability affects both client and server implementations.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

libssh: 0.8.0 - 0.9.3

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External links
http://www.libssh.org/security/advisories/CVE-2020-1730.txt

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.