CVE-2021-33500

HIGH
7.5
CVSS Score
Published: May 21, 2021 at 07:42 PM UTC
Updated: June 17, 2026 at 03:54 AM UTC
1 product affected across 1 vendorPuTTY· also runs on 1 platform

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Severity
HIGH7.5
Exploit prediction
EPSS 2%

Description

PuTTY before 0.75 on Windows allows remote servers to cause a denial of service (Windows GUI hang) by telling the PuTTY window to change its title repeatedly at high speed, which results in many SetWindowTextA or SetWindowTextW calls. NOTE: the same attack methodology may affect some OS-level GUIs on Linux or other platforms for similar reasons.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 0.75
Affected range stops below 0.75, so it looks safe — our inference, not a vendor statement
microsoft-windows (environment)

Runs on — not affected

The affected product only carries this flaw when running on these platforms. The platforms themselves are not vulnerable.

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

References (3)

CVSS

7.5HIGHmitre
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
NVD-CWE-noinfo

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