A flaw in the networking code handling DNS-over-TLS queries… (CVE-2023-4236)

Summary

Vulnerability reported (CVE-2023-4236). Risk of unauthorized operations or information disclosure. Exploitable via named.

Original description

The description as published by the source.

A flaw in the networking code handling DNS-over-TLS queries may cause named to terminate unexpectedly due to an assertion failure. This happens when internal data structures are incorrectly reused under significant DNS-over-TLS query load.
This issue affects BIND 9 versions 9.18.0 through 9.18.18 and 9.18.11-S1 through 9.18.18-S1.

Source: OSV.dev (Open Source Vulnerabilities) NVD OSV

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 CVE-2023-4236 has been found.
Attackers can target a specific entry point like named over the network to misuse the product.
Risk of unauthorized operations or information disclosure.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "CVE-2023-4236" on the vendor's site.

CVE-2023-4236
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: named
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.

❓ What is the problem

A vulnerability (unclassified) has been reported. Attackers reach the vulnerable code path via named without authentication.

📍 Affected scope

Check the vendor advisory for the affected versions. Attack surface: named.

🔥 Severity

Severity: ?. Risk of unauthorized operations or information disclosure.

🔧 How to fix

Update to the patched release per vendor advisory.

🛡️ Workaround

Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.

🔍 Detection

Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.

Response actions

Concrete steps and command examples for SOC/SRE teams to execute in order

1
Identify exposure identify
```
Audit SBOM/dependencies for affected components.
```
資産台帳・SBOM・依存マニフェストで影響コンポーネントを特定する。
2
Post-deployment verification verify
```
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。

Fix status by distribution

Fixed packages published by each distribution for this CVE

Alpine Linux ALPINE-CVE-2023-4236 bind Fixed in: 9.18.19-r0
Debian DEBIAN-CVE-2023-4236 bind9 Fixed in: 1:9.18.19-1~deb12u1

A flaw in the networking code handling DNS-over-TLS queries may cause `named` to terminate unexpectedly due to an…