How severe is CVE-2021-43202?

CVE-2021-43202 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-2021-43202 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (60th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-43202?

CVE-2021-43202 affects Jetbrains Teamcity. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-43202?

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-2021-43202 published?

CVE-2021-43202 was published on 2021-11-30 and last updated on 2026-06-17.

CVE-2021-43202

CVE-2021-43202 is a critical-severity vulnerability in Jetbrains Teamcity 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.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 1% (60th percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Jetbrains Teamcity
Published: 2021-11-30
Last modified: 2026-06-17

Description

In JetBrains TeamCity before 2021.1.3, the X-Frame-Options header is missing in some cases.

Frequently asked questions

What is CVE-2021-43202?: In JetBrains TeamCity before 2021.1.3, the X-Frame-Options header is missing in some cases.
How severe is CVE-2021-43202?: CVE-2021-43202 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-2021-43202 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (60th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-43202?: CVE-2021-43202 affects Jetbrains Teamcity. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-43202?: 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-2021-43202 published?: CVE-2021-43202 was published on 2021-11-30 and last updated on 2026-06-17.

References

https://blog.jetbrains.com/blog/2021/11/08/jetbrains-security-bulletin-q3-2021/

Affected products (1)

cpe:2.3:a:jetbrains:teamcity:*:*:*:*:*:*:*:*

More vulnerabilities in Jetbrains Teamcity

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CVE-2022-24331 — Critical (CVSS 9.8): In JetBrains TeamCity before 2021.1.4, GitLab authentication impersonation was possible.

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