| 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, ELA-437-1 |
| Debian Bugs | 989095 |
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|---|---|---|
| nginx (PTS) | jessie, jessie (lts) | 1.6.2-5+deb8u10 | fixed |
| stretch (security) | 1.10.3-1+deb9u7 | fixed | |
| stretch (lts), stretch | 1.10.3-1+deb9u8 | fixed | |
| buster (security), buster, buster (lts) | 1.14.2-2+deb10u5 | fixed | |
| bullseye (security), bullseye | 1.18.0-6.1+deb11u3 | fixed | |
| bookworm | 1.22.1-9 | fixed | |
| sid, trixie | 1.26.0-3 | fixed |
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs |
|---|---|---|---|---|---|---|
| nginx | source | jessie | 1.6.2-5+deb8u8 | ELA-437-1 | ||
| nginx | source | stretch | 1.10.3-1+deb9u6 | DLA-2670-1 | ||
| nginx | source | buster | 1.14.2-2+deb10u4 | DSA-4921-1 | ||
| nginx | source | (unstable) | 1.18.0-6.1 | 989095 |
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)