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6.8 Medium

CVE-2025-26465 Openssh: machine-in-the-middle attack if verifyhostkeydns is enabled

Description

A vulnerability was found in OpenSSH when the VerifyHostKeyDNS option is enabled. A machine-in-the-middle attack can be performed by a malicious machine impersonating a legit server. This issue occurs due to how OpenSSH mishandles error codes in specific conditions when verifying the host key. For an attack to be considered successful, the attacker needs to manage to exhaust the client's memory resource first, turning the attack complexity high.

CVSS 3.1 detail

Vector CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N

Exploitable remotely over the network, without an account and if a user takes an action; an attacker can seriously compromise confidentiality, integrity or availability.

Attack vector
Network
Attack complexity
High
Privileges required
None
Interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None

Affected products and versions

Product Affected versions Fixed in
Red Hat Enterprise Linux 8 Versions not published
Red Hat Enterprise Linux 9 Versions not published
Red Hat Enterprise Linux 9.4 Extended Update Support Versions not published
Red Hat Discovery 1.14 1.14 earliest → < 1.14.3-1748529279 1.14.3-1748529279
Red Hat Enterprise Linux 10 Versions not published
Red Hat Enterprise Linux 6 Versions not published
Red Hat Enterprise Linux 7 Versions not published
Red Hat OpenShift Container Platform 4 Versions not published
SIMATIC S7-1500 CPU 1518-4 PN/DP MFP 3.1 3.1.5 → latest No fix stated
Show the 3 other branches
Product Affected versions Fixed in
SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP 3.1 3.1.5 → latest No fix stated
SIPLUS S7-1500 CPU 1518-4 PN/DP MFP 3.1 3.1.5 → latest No fix stated
SIDIS Secured SmartPlug 7.26 earliest → < 7.26.0310 7.26.0310

References

Timeline

  1. Published
  2. Last modified

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