How severe is CVE-2020-21699?

CVE-2020-21699 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2020-21699 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (47th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-21699?

CVE-2020-21699 affects Alibaba Tengine. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-21699?

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

When was CVE-2020-21699 published?

CVE-2020-21699 was published on 2023-08-22 and last updated on 2026-06-17.

CVE-2020-21699

CVE-2020-21699 is a high-severity vulnerability in Alibaba Tengine with a CVSS 3.x base score of 7.5. 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-190.

Key facts

Severity: High (CVSS 3.x base score 7.5)
EPSS exploit prediction: 1% (47th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-190
Affected product: Alibaba Tengine
Published: 2023-08-22
Last modified: 2026-06-17

Description

The web server Tengine 2.2.2 developed in the Nginx version from 0.5.6 thru 1.13.2 is vulnerable to an integer overflow vulnerability in the nginx range filter module, resulting in the leakage of potentially sensitive information triggered by specially crafted requests.

Frequently asked questions

What is CVE-2020-21699?: The web server Tengine 2.2.2 developed in the Nginx version from 0.5.6 thru 1.13.2 is vulnerable to an integer overflow vulnerability in the nginx range filter module, resulting in the leakage of potentially sensitive information triggered by specially crafted requests.
How severe is CVE-2020-21699?: CVE-2020-21699 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2020-21699 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (47th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-21699?: CVE-2020-21699 affects Alibaba Tengine. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-21699?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2020-21699 published?: CVE-2020-21699 was published on 2023-08-22 and last updated on 2026-06-17.

References

https://github.com/ZxDecide/Nginx-variants/blob/master/%E9%99%84%E4%BB%B6%28Tengine%29.docx

Affected products (1)

cpe:2.3:a:alibaba:tengine:2.2.2:*:*:*:*:nginx:*:*

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