Is CVE-2021-33500 in the CISA KEV catalog?

No. CVE-2021-33500 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2021-33500?

CVE-2021-33500 has a CVSS v3 base score of 7.5 (HIGH).

What is the EPSS score for CVE-2021-33500?

CVE-2021-33500 has an EPSS score of 1.97% (78th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2021-33500?

Upgrade PuTTY to 0.75 or later.

CVE & CISA-KEV Catalog

CVE-2021-33500

HIGHEPSS 78th pctl

7.5

CVSS v3

NVD

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.

How to fix

Remediation Available

PuTTYWindows application

Affected:0.75Fixed in:0.75Simon Tatham

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityNone

IntegrityNone

AvailabilityHigh

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

Exploit Intelligence

1.97%probability of exploitation in 30 days

78thpercentile

Elevated risk: more likely to be exploited than 78% of all known CVEs.

References

Exploit2

Third-Party Advisory1

chiark.greenend.org.uk

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2024-11-21.