---
cve: "CVE-2021-23017"
severity: "LOW"
cvss: 3.1
epss: "53.5%"
vendor: "n/a"
kev: false
exploited: false
published: "2021-06-01 13:15:07"
tags: [cve, security, low]
source: tsecurity.de CVE-Dossier
exported: "2026-09-17T00:41:11+02:00"
---

# CVE-2021-23017

> 3.1 LOW · 🧪 PoC

## Beschreibung

A security issue in nginx resolver was identified, which might allow an attacker who is able to forge UDP packets from the DNS server to cause 1-byte memory overwrite, resulting in worker process crash or potential other impact.

## Exploit-Evidenz

- [EDB-50973 — Nginx 1.20.0 - Denial of Service (DOS)](https://www.exploit-db.com/exploits/50973)

## Patch verfügbar (OSV)

- 98a892514206ee63d418d9f355c92b6d4ce6113a (Commit)
- a1017ea9856315486e24f8712d7b20dfd5312ceb (Commit)

## Referenzen

- <https://support.f5.com/csp/article/K12331123%2C>
- <http://mailman.nginx.org/pipermail/nginx-announce/2021/000300.html>
- <https://lists.apache.org/thread.html/r6fc5c57b38e93e36213e9a18c8a4e5dbd5ced1c7e57f08a1735975ba%40%3Cnotifications.apisix.apache.org%3E>
- <https://lists.apache.org/thread.html/r37e6b2165f7c910d8e15fd54f4697857619ad2625f56583802004009%40%3Cnotifications.apisix.apache.org%3E>
- <https://lists.apache.org/thread.html/rf318aeeb4d7a3a312734780b47de83cefb7e6995da0b2cae5c28675c%40%3Cnotifications.apisix.apache.org%3E>
- <https://lists.apache.org/thread.html/r4d4966221ca399ce948ef34884652265729d7d9ef8179c78d7f17e7f%40%3Cnotifications.apisix.apache.org%3E>
- <https://lists.apache.org/thread.html/rf232eecd47fdc44520192810560303073cefd684b321f85e311bad31%40%3Cnotifications.apisix.apache.org%3E>
- <https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/GNKOP2JR5L7KCIZTJRZDCUPJTUONMC5I/>
- <https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/7SFVYHC7OXTEO4SMBWXDVK6E5IMEYMEE/>
- <https://www.oracle.com/security-alerts/cpuoct2021.html>
- <https://security.netapp.com/advisory/ntap-20210708-0006/>
- <https://www.oracle.com/security-alerts/cpujan2022.html>
- <https://www.oracle.com/security-alerts/cpuapr2022.html>
- <http://packetstormsecurity.com/files/167720/Nginx-1.20.0-Denial-Of-Service.html>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2021-23017) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_