Multiple vulnerabilities in OpenSSH



| Updated: 2025-02-21
Risk Medium
Patch available NO
Number of vulnerabilities 2
CVE-ID CVE-2025-26465
CVE-2025-26466
CWE-ID CWE-300
CWE-20
Exploitation vector Network
Public exploit Public exploit code for vulnerability #2 is available.
Vulnerable software
 OpenSSH
Server applications / Remote management servers, RDP, SSH

Vendor OpenSSH

Security Bulletin

This security bulletin contains information about 2 vulnerabilities.

1) Man-in-the-Middle (MitM) attack

EUVDB-ID: #VU104035

Risk: Medium

CVSSv4.0: 2.1 [CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:A/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2025-26465

CWE-ID: CWE-300 - Channel Accessible by Non-Endpoint ('Man-in-the-Middle')

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform MitM attack.

The vulnerability exists due to incorrect processing of user-supplied data in ssh(1). A remote attacker can perform server impersonation when VerifyHostKeyDNS enabled.

Mitigation

Cybersecurity Help is currently unaware of any official solution to address this vulnerability.

Vulnerable software versions

OpenSSH: 9.5p1 - 9.9p1

CPE2.3 External links

https://www.qualys.com/2025/02/18/openssh-mitm-dos.txt


Q & A

Can this vulnerability be exploited remotely?

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

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected application in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

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

2) Input validation error

EUVDB-ID: #VU104034

Risk: Medium

CVSSv4.0: 7.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:P/U:Green]

CVE-ID: CVE-2025-26466

CWE-ID: CWE-20 - Improper input validation

Exploit availability: Yes

Description

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

The vulnerability exists due to insufficient validation of user-supplied input related to SSH2_MSG_PING handling in sshd(8). A remote attacker can send specially crafted packets to the server and perform a denial of service (DoS) attack.

Mitigation

Cybersecurity Help is currently unaware of any official solution to address this vulnerability.

Vulnerable software versions

OpenSSH: 9.5p1 - 9.9p1

CPE2.3 External links

https://www.qualys.com/2025/02/18/openssh-mitm-dos.txt


Q & A

Can this vulnerability be exploited remotely?

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

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected application in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.



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