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.

Published: 2023-08-22 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2020-21699 is rated Moderate Risk (46.7/100): CVSS High severity, with low exploitation likelihood (EPSS 0.66%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2020-21699

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.26% 0.66% +0.40%
2 2026-05-17 0.23% 0.26% +0.03%
3 2025-11-21 — 0.23% —

Full EPSS history (9 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-21699

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 3.6 [email protected]

Weakness enumeration for CVE-2020-21699

OS Trackers for CVE-2020-21699

vendor priority summary link
ubuntu medium CVE-2020-21699 medium priority: Ubuntu including 1 source packages (nginx), 7 status rows across 7 suites (bionic, focal, jammy, lunar, trusty, upstream, xenial): not-affected 6, needs-triage 1. https://ubuntu.com/security/CVE-2020-21699

Affected software / configurations for CVE-2020-21699

Vendor Product Version Raw CPE
alibaba tengine 2.2.2 cpe:2.3:a:alibaba:tengine:2.2.2:*:*:*:*:nginx:*:*

References for CVE-2020-21699

cvelogic Threat Intelligence