CVE-2021-23017 EXPLOIT
7.7
HIGH · CVSS 3.1 · EPSS 53.5% (pctl 99)
Patch early
A public exploit exists.
Description
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.
Scoring
| CVSS | 7.7 (HIGH, v3.1) |
|---|---|
| Vector | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L |
| EPSS | 53.46% — more likely to be exploited than 99% of all CVEs |
| Weakness | CWE-193 |
| On CISA KEV | no |
| Public exploit | yes |
| Published | 2021-06-01 |
| Last modified | 2026-06-17 |
Affected (13)
| Vendor | Product |
|---|---|
| f5 | nginx |
| fedoraproject | fedora |
| netapp | ontap select deploy administration utility |
| openresty | openresty |
| oracle | blockchain platform |
| oracle | communications control plane monitor |
| oracle | communications fraud monitor |
| oracle | communications operations monitor |
| oracle | communications session border controller |
| oracle | enterprise communications broker |
| oracle | enterprise session border controller |
| oracle | enterprise telephony fraud monitor |
| oracle | goldengate |
Public exploits
| Source | Title | Date |
|---|---|---|
| exploit-db | Nginx 1.20.0 - Denial of Service (DOS) | 2022-07-11 |
References
- http://mailman.nginx.org/pipermail/nginx-announce/2021/000300.html
- http://packetstormsecurity.com/files/167720/Nginx-1.20.0-Denial-Of-Service.html
- https://lists.apache.org/thread.html/r37e6b2165f7c910d8e15fd54f4697857619ad2625f56583802004009%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/r6fc5c57b38e93e36213e9a18c8a4e5dbd5ced1c7e57f08a1735975ba%40%3Cnotifications.apisix.apache.org%3E
- https://lists.apache.org/thread.html/rf232eecd47fdc44520192810560303073cefd684b321f85e311bad31%40%3Cnotifications.apisix.apache.org%3E
- https://lists.apache.org/thread.html/rf318aeeb4d7a3a312734780b47de83cefb7e6995da0b2cae5c28675c%40%3Cnotifications.apisix.apache.org%3E
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/7SFVYHC7OXTEO4SMBWXDVK6E5IMEYMEE/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/GNKOP2JR5L7KCIZTJRZDCUPJTUONMC5I/
- https://security.netapp.com/advisory/ntap-20210708-0006/
- https://support.f5.com/csp/article/K12331123%2C
- https://www.oracle.com/security-alerts/cpuapr2022.html
- https://www.oracle.com/security-alerts/cpujan2022.html
- https://www.oracle.com/security-alerts/cpuoct2021.html
- http://mailman.nginx.org/pipermail/nginx-announce/2021/000300.html
- http://packetstormsecurity.com/files/167720/Nginx-1.20.0-Denial-Of-Service.html
- https://lists.apache.org/thread.html/r37e6b2165f7c910d8e15fd54f4697857619ad2625f56583802004009%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/r6fc5c57b38e93e36213e9a18c8a4e5dbd5ced1c7e57f08a1735975ba%40%3Cnotifications.apisix.apache.org%3E
- https://lists.apache.org/thread.html/rf232eecd47fdc44520192810560303073cefd684b321f85e311bad31%40%3Cnotifications.apisix.apache.org%3E
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