How severe is CVE-2021-37909?

CVE-2021-37909 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-37909 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (78th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-37909?

CVE-2021-37909 affects Tssservisignadapter Project Tssservisignadapter. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-37909?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2021-37909 published?

CVE-2021-37909 was published on 2021-09-15 and last updated on 2026-06-17.

CVE-2021-37909

CVE-2021-37909 is a critical-severity vulnerability in Tssservisignadapter Project Tssservisignadapter with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-20.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 2% (78th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: Tssservisignadapter Project Tssservisignadapter
Published: 2021-09-15
Last modified: 2026-06-17

Description

WriteRegistry function in TSSServiSign component does not filter and verify users’ input, remote attackers can rewrite to the registry without permissions thus perform hijack attacks to execute arbitrary code.

Frequently asked questions

What is CVE-2021-37909?: WriteRegistry function in TSSServiSign component does not filter and verify users’ input, remote attackers can rewrite to the registry without permissions thus perform hijack attacks to execute arbitrary code.
How severe is CVE-2021-37909?: CVE-2021-37909 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-37909 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (78th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-37909?: CVE-2021-37909 affects Tssservisignadapter Project Tssservisignadapter. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-37909?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2021-37909 published?: CVE-2021-37909 was published on 2021-09-15 and last updated on 2026-06-17.

References

https://www.twcert.org.tw/tw/cp-132-5093-76f04-1.html

Affected products (1)

cpe:2.3:a:tssservisignadapter_project:tssservisignadapter:*:*:*:*:*:windows:*:*

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