| Name | CVE-2021-23017 |
| 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. |
| Source | CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) |
| References | DLA-2670-1, DSA-4921-1 |
| Debian Bugs | 989095 |
Vulnerable and fixed packages
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|
| nginx (PTS) | buster | 1.14.2-2+deb10u4 | fixed |
| buster (security) | 1.14.2-2+deb10u5 | fixed |
| bullseye (security), bullseye | 1.18.0-6.1+deb11u3 | fixed |
| bookworm | 1.22.1-9 | fixed |
| sid, trixie | 1.24.0-2 | fixed |
The information below is based on the following data on fixed versions.
Notes
https://www.openwall.com/lists/oss-security/2021/05/25/5
Patch: http://nginx.org/download/patch.2021.resolver.txt
Fixed by: https://github.com/nginx/nginx/commit/7199ebc203f74fd9e44595474de6bdc41740c5cf (1.20.1)