Vulnerability in Ntp (CVE-2015-3405, CVSS 7.5)

Summary

Vulnerability in Ntp (CVE-2015-3405). Confidential information can be exposed externally.

Original description

The description as published by the source.

ntp-keygen in ntp 4.2.8px before 4.2.8p2-RC2 and 4.3.x before 4.3.12 does not generate MD5 keys with sufficient entropy on big endian machines when the lowest order byte of the temp variable is between 0x20 and 0x7f and not #, which might allow remote attackers to obtain the value of generated MD5 keys via a brute force attack with the 93 possible keys.

Source: NIST National Vulnerability Database NVD

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-2015-3405 has been found in Ntp.
Confidential information can be exposed externally. CVSS score: 7.5/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Ntp CVE-2015-3405" on the vendor's site.

CVE-2015-3405 (Ntp) — CWE-331 / CVSS v3 7.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
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 (CWE-331) exists in Ntp.

📍 Affected scope

Check the vendor advisory for the affected versions of Ntp.

🔥 Severity

Severity: High (CVSS 7.5/10). Confidential information can be exposed externally.

🔧 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. Run grep -r 'Ntp' . 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 exposure identify
```
grep -r 'Ntp' . | 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 Ntp を grep し、稼働しているサービス・バージョンを把握する。
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

Debian DEBIAN-CVE-2015-3405 ntp Fixed in: 1:4.2.6.p5+dfsg-7

Summary

Original description

Auto-generated summary

Response actions

Fix status by distribution

References