CVE-2021-36367 - Vulnerability Details - OpenCVE

PuTTY through 0.75 proceeds with establishing an SSH session even if it has never sent a substantive authentication response. This makes it easier for an attacker-controlled SSH server to present a later spoofed authentication prompt (that the attacker can use to capture credential data, and use that data for purposes that are undesired by the client user).

No CVSS v4.0

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact High

Integrity Impact High

Availability Impact None

User Interaction Required

No CVSS v3.0

Access Vector Network

Access Complexity Medium

Authentication None

Confidentiality Impact Partial

Integrity Impact Partial

Availability Impact None

This CVE is not in the KEV list.

The EPSS score is 0.00135.

Exploitation none

Automatable no

Technical Impact total

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

n/a

n/a

affected

Version	Status	Constraints
`n/a`	affected	—

Configuration 1 [-]

cpe:2.3:a:putty:putty:*:*:*:*:*:*:*:*

No data.

No data.

Subscriptions

Vendors	Products
Putty Subscribe	Putty Subscribe

Tracking

Sign in to view the affected projects.

Advisories

Source	ID	Title
Debian DLA	DLA-3794-1	putty security update
Debian DSA	DSA-5588-1	putty security update

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References

Link	Providers
https://git.tartarus.org/?p=simon/putty.git%3Ba=commit%3Bh=1dc5659aa62848f0aeb5de7bd3839fecc7debefa
https://lists.debian.org/debian-lts-announce/2024/04/msg00016.html
https://www.chiark.greenend.org.uk/~sgtatham/putty/changes.html
https://www.debian.org/security/2023/dsa-5588

History

Wed, 25 Feb 2026 18:15:00 +0000

Type	Values Removed	Values Added
CPEs		cpe:2.3:a:putty:putty:-:::::::*
Metrics		ssvc `{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}`

MITRE

Status: PUBLISHED

Assigner: mitre

Published: 2021-07-09T00:00:00.000Z

Updated: 2024-08-04T00:54:51.472Z

Reserved: 2021-07-09T00:00:00.000Z

Link: CVE-2021-36367

Vulnrichment

Updated: 2024-08-04T00:54:51.472Z

NVD

Status : Modified

Published: 2021-07-09T21:15:08.540

Modified: 2024-11-21T06:13:36.733

Link: CVE-2021-36367

Redhat

No data.

OpenCVE Enrichment

No data.

Weaknesses

CWE-345

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