Vulnerability · Published Jun 1, 2021 · Assigned by f5
CVE-2021-23017
High 7.7
In plain English
A high-severity security flaw in Nginx Web Server, Nginx Plus. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 53.5% (higher than 99% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code. Fixed versions are available - upgrade the affected package.
Severity (CVSS NVD)7.7High
Exploit odds (30 days)53.5%top 1.0% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack tooling1Public PoC
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux:8 | nginx | 1:1.18.0-3.module_el8.5.0+36+48437aab.1.alma | ALSA-2021:2259 |
| AlmaLinux:8 | nginx | 1:1.20.1-1.module_el8.6.0+2782+a022aca3.alma | ALSA-2022:0323 |
| AlmaLinux:8 | nginx | 1:1.16.1-2.module_el8.4.0+2470+68135136.1.alma | ALSA-2021:2290 |
| AlmaLinux:8 | nginx | 1:1.16.1-2.module_el8.5.0+35+6a1225c3.1.alma | ALSA-2021:2290 |
| AlmaLinux:8 | nginx | 1:1.18.0-3.module_el8.4.0+2472+f736ed63.1.alma | ALSA-2021:2259 |
| AlmaLinux:8 | nginx | 1:1.20.1-1.module_el8.5.0+2611+ab304644.alma | ALSA-2022:0323 |
| AlmaLinux:8 | nginx-all-modules | 1:1.20.1-1.module_el8.6.0+2782+a022aca3.alma | ALSA-2022:0323 |
| AlmaLinux:8 | nginx-all-modules | 1:1.18.0-3.module_el8.4.0+2472+f736ed63.1.alma | ALSA-2021:2259 |
| AlmaLinux:8 | nginx-all-modules | 1:1.16.1-2.module_el8.4.0+2470+68135136.1.alma | ALSA-2021:2290 |
| AlmaLinux:8 | nginx-all-modules | 1:1.20.1-1.module_el8.5.0+2611+ab304644.alma | ALSA-2022:0323 |
| AlmaLinux:8 | nginx-filesystem | 1:1.16.1-2.module_el8.4.0+2470+68135136.1.alma | ALSA-2021:2290 |
| AlmaLinux:8 | nginx-filesystem | 1:1.18.0-3.module_el8.4.0+2472+f736ed63.1.alma | ALSA-2021:2259 |
| AlmaLinux:8 | nginx-filesystem | 1:1.20.1-1.module_el8.6.0+2782+a022aca3.alma | ALSA-2022:0323 |
| AlmaLinux:8 | nginx-filesystem | 1:1.20.1-1.module_el8.5.0+2611+ab304644.alma | ALSA-2022:0323 |
| AlmaLinux:8 | nginx-mod-http-image-filter | 1:1.20.1-1.module_el8.5.0+2611+ab304644.alma | ALSA-2022:0323 |
| AlmaLinux:8 | nginx-mod-http-image-filter | 1:1.18.0-3.module_el8.4.0+2472+f736ed63.1.alma | ALSA-2021:2259 |
| AlmaLinux:8 | nginx-mod-http-image-filter | 1:1.18.0-3.module_el8.5.0+36+48437aab.1.alma | ALSA-2021:2259 |
| AlmaLinux:8 | nginx-mod-http-image-filter | 1:1.16.1-2.module_el8.4.0+2470+68135136.1.alma | ALSA-2021:2290 |
| AlmaLinux:8 | nginx-mod-http-image-filter | 1:1.16.1-2.module_el8.5.0+35+6a1225c3.1.alma | ALSA-2021:2290 |
| AlmaLinux:8 | nginx-mod-http-image-filter | 1:1.20.1-1.module_el8.6.0+2782+a022aca3.alma | ALSA-2022:0323 |
| AlmaLinux:8 | nginx-mod-http-perl | 1:1.20.1-1.module_el8.5.0+2611+ab304644.alma | ALSA-2022:0323 |
| AlmaLinux:8 | nginx-mod-http-perl | 1:1.18.0-3.module_el8.4.0+2472+f736ed63.1.alma | ALSA-2021:2259 |
| AlmaLinux:8 | nginx-mod-http-perl | 1:1.18.0-3.module_el8.5.0+36+48437aab.1.alma | ALSA-2021:2259 |
| AlmaLinux:8 | nginx-mod-http-perl | 1:1.16.1-2.module_el8.4.0+2470+68135136.1.alma | ALSA-2021:2290 |
| AlmaLinux:8 | nginx-mod-http-perl | 1:1.16.1-2.module_el8.5.0+35+6a1225c3.1.alma | ALSA-2021:2290 |
| AlmaLinux:8 | nginx-mod-http-perl | 1:1.20.1-1.module_el8.6.0+2782+a022aca3.alma | ALSA-2022:0323 |
| AlmaLinux:8 | nginx-mod-http-xslt-filter | 1:1.20.1-1.module_el8.5.0+2611+ab304644.alma | ALSA-2022:0323 |
| AlmaLinux:8 | nginx-mod-http-xslt-filter | 1:1.16.1-2.module_el8.4.0+2470+68135136.1.alma | ALSA-2021:2290 |
| AlmaLinux:8 | nginx-mod-http-xslt-filter | 1:1.16.1-2.module_el8.5.0+35+6a1225c3.1.alma | ALSA-2021:2290 |
| AlmaLinux:8 | nginx-mod-http-xslt-filter | 1:1.18.0-3.module_el8.4.0+2472+f736ed63.1.alma | ALSA-2021:2259 |
| AlmaLinux:8 | nginx-mod-http-xslt-filter | 1:1.18.0-3.module_el8.5.0+36+48437aab.1.alma | ALSA-2021:2259 |
| AlmaLinux:8 | nginx-mod-http-xslt-filter | 1:1.20.1-1.module_el8.6.0+2782+a022aca3.alma | ALSA-2022:0323 |
| AlmaLinux:8 | nginx-mod-mail | 1:1.18.0-3.module_el8.4.0+2472+f736ed63.1.alma | ALSA-2021:2259 |
| AlmaLinux:8 | nginx-mod-mail | 1:1.16.1-2.module_el8.4.0+2470+68135136.1.alma | ALSA-2021:2290 |
| AlmaLinux:8 | nginx-mod-mail | 1:1.16.1-2.module_el8.5.0+35+6a1225c3.1.alma | ALSA-2021:2290 |
| AlmaLinux:8 | nginx-mod-mail | 1:1.18.0-3.module_el8.5.0+36+48437aab.1.alma | ALSA-2021:2259 |
| AlmaLinux:8 | nginx-mod-mail | 1:1.20.1-1.module_el8.6.0+2782+a022aca3.alma | ALSA-2022:0323 |
| AlmaLinux:8 | nginx-mod-mail | 1:1.20.1-1.module_el8.5.0+2611+ab304644.alma | ALSA-2022:0323 |
| AlmaLinux:8 | nginx-mod-stream | 1:1.20.1-1.module_el8.6.0+2782+a022aca3.alma | ALSA-2022:0323 |
| AlmaLinux:8 | nginx-mod-stream | 1:1.18.0-3.module_el8.4.0+2472+f736ed63.1.alma | ALSA-2021:2259 |
| AlmaLinux:8 | nginx-mod-stream | 1:1.18.0-3.module_el8.5.0+36+48437aab.1.alma | ALSA-2021:2259 |
| AlmaLinux:8 | nginx-mod-stream | 1:1.16.1-2.module_el8.4.0+2470+68135136.1.alma | ALSA-2021:2290 |
| AlmaLinux:8 | nginx-mod-stream | 1:1.16.1-2.module_el8.5.0+35+6a1225c3.1.alma | ALSA-2021:2290 |
| AlmaLinux:8 | nginx-mod-stream | 1:1.20.1-1.module_el8.5.0+2611+ab304644.alma | ALSA-2022:0323 |
| Alpine:v3.20 | nginx | 1.20.1-r0 | ALPINE-CVE-2021-23017 |
| Alpine:v3.21 | nginx | 1.20.1-r0 | ALPINE-CVE-2021-23017 |
| Alpine:v3.22 | nginx | 1.20.1-r0 | ALPINE-CVE-2021-23017 |
| Alpine:v3.23 | nginx | 1.20.1-r0 | ALPINE-CVE-2021-23017 |
| Alpine:v3.24 | nginx | 1.20.1-r0 | ALPINE-CVE-2021-23017 |
| Debian:12 | nginx | 1.18.0-6.1 | DEBIAN-CVE-2021-23017 |
| Debian:13 | nginx | 1.18.0-6.1 | DEBIAN-CVE-2021-23017 |
| Debian:14 | nginx | 1.18.0-6.1 | DEBIAN-CVE-2021-23017 |
| Rocky Linux:8 | nginx | 1:1.20.1-1.module+el8.5.0+729+3f70613e | RLSA-2022:0323 |
| Rocky Linux:8 | nginx | 1:1.20.1-1.module+el8.6.0+791+48a2bb9d | RLSA-2022:0323 |
| Rocky Linux:8 | nginx | 1:1.16.1-2.module+el8.4.0+543+efbf198b.1 | RLSA-2021:2290 |
| Rocky Linux:8 | nginx | 1:1.18.0-3.module+el8.4.0+544+e40554cf.1 | RLSA-2021:2259 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| n/a | Nginx Web Server, Nginx Plus | Nginx Web Server versions 0.6.18 thru 1.20.0 before 1.20.1, Nginx plus versions R13 thru R23 before R23 P1. Nginx plus version R24 before R24 P1 |
Weakness: CWE-193
References
- https://support.f5.com/csp/article/K12331123%2C x_refsource_MISC
- http://mailman.nginx.org/pipermail/nginx-announce/2021/000300.html x_refsource_MISC
- [apisix-notifications] 20210607 [GitHub] [apisix-website] Serendipity96 opened a new pull request #362: feat: add new blog mailing-list, x_refsource_MLIST
- [apisix-notifications] 20210608 [GitHub] [apisix-website] liuxiran commented on a change in pull request #362: docs: added "Apache APISIX not affected by NGINX CVE-2021-23017" mailing-list, x_refsource_MLIST
- [apisix-notifications] 20210608 [GitHub] [apisix-website] netlify[bot] edited a comment on pull request #362: docs: added "Apache APISIX not affected by NGINX CVE-2021-23017" mailing-list, x_refsource_MLIST
- [apisix-notifications] 20210608 [GitHub] [apisix-website] liuxiran merged pull request #362: docs: added "Apache APISIX not affected by NGINX CVE-2021-23017" mailing-list, x_refsource_MLIST
- [apisix-notifications] 20210608 [apisix-website] branch master updated: docs: added "Apache APISIX not affected by NGINX CVE-2021-23017" (#362) mailing-list, x_refsource_MLIST
- FEDORA-2021-b37cffac0d vendor-advisory, x_refsource_FEDORA
- FEDORA-2021-393d698493 vendor-advisory, x_refsource_FEDORA
- https://www.oracle.com/security-alerts/cpuoct2021.html x_refsource_MISC
- https://security.netapp.com/advisory/ntap-20210708-0006/ x_refsource_CONFIRM
- https://www.oracle.com/security-alerts/cpujan2022.html x_refsource_MISC
- https://www.oracle.com/security-alerts/cpuapr2022.html x_refsource_MISC
- http://packetstormsecurity.com/files/167720/Nginx-1.20.0-Denial-Of-Service.html x_refsource_MISC