Vulnerability in bind9
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as DEBIAN-CVE-2021-25216 has been found in bind9.
Successful exploitation can lead to full system takeover.
What to do: upgrade bind9 to 1:9.16.15-1 or later.
If unsure, ask your IT team or search "bind9 DEBIAN-CVE-2021-25216" on the vendor's site.
DEBIAN-CVE-2021-25216 (bind9)
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Patched: 1:9.16.15-1 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (unclassified) exists in bind9.
Check the vendor advisory for the affected versions of bind9.
Severity: ?. Successful exploitation can lead to full system takeover.
Update to 1:9.16.15-1.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'bind9' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1
Identify exposureidentify
grep -r 'bind9' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
bind9を grep し、稼働しているサービス・バージョンを把握する。 -
2
Apply patchpatch
Upgrade bind9 to 1:9.16.15-1ステージング環境で 1:9.16.15-1 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
3
Post-deployment verificationverify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
| Ecosystem | Package | Affected | Fixed |
|---|---|---|---|
| Debian:12 | bind9 |
< 1:9.16.15-1 |
1:9.16.15-1 |
| Debian:13 | bind9 |
< 1:9.16.15-1 |
1:9.16.15-1 |
| Debian:14 | bind9 |
< 1:9.16.15-1 |
1:9.16.15-1 |
Original description The description as published by the source.
In BIND 9.5.0 -> 9.11.29, 9.12.0 -> 9.16.13, and versions BIND 9.11.3-S1 -> 9.11.29-S1 and 9.16.8-S1 -> 9.16.13-S1 of BIND Supported Preview Edition, as well as release versions 9.17.0 -> 9.17.1 of the BIND 9.17 development branch, BIND servers are vulnerable if they are running an affected version and are configured to use GSS-TSIG features. In a configuration which uses BIND's default settings the vulnerable code path is not exposed, but a server can be rendered vulnerable by explicitly setting values for the tkey-gssapi-keytab or tkey-gssapi-credential configuration options. Although the default configuration is not vulnerable, GSS-TSIG is frequently used in networks where BIND is integrated with Samba, as well as in mixed-server environments that combine BIND servers with Active Directory domain controllers. For servers that meet these conditions, the ISC SPNEGO implementation is vulnerable to various attacks, depending on the CPU architecture for which BIND was built: For named binaries compiled for 64-bit platforms, this flaw can be used to trigger a buffer over-read, leading to a server crash. For named binaries compiled for 32-bit platforms, this flaw can be used to trigger a server crash due to a buffer overflow and possibly also to achieve remote code execution. We have determined that standard SPNEGO implementations are available in the MIT and Heimdal Kerberos libraries, which support a broad range of operating systems, rendering the ISC implementation unnecessary…
Source: OSV.dev (Open Source Vulnerabilities) OSV
References
- advisory security-tracker.debian.org