CVE-2015-3405

What it is

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.

At a glance

Exploitability

Can be exploited over the network without logging in. High risk of data exposure.

Exploit odds

5.3% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2017-08-09 16:29 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 00:25 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 5.3% in the next 30 days (EPSS).
• Severity: 7.5 HIGH (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2017-08-09 16:29 UTC

Last modified

2026-06-17 00:25 UTC

Exploit probability

5.3% · EPSS, next 30 days

Weakness

CWE-331

Record status

Modified

Affected

• Ntp 4.2.8
• Ntp 4.3.0
• Ntp 4.3.1
• Ntp 4.3.2
• Ntp 4.3.3
• Ntp 4.3.4
• Ntp 4.3.5
• Ntp 4.3.6

Attack profile CVSS 3.0 · 7.5

Attack vector

Network

Complexity

Low

Privileges needed

None

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

None

Availability

None

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2015-3405.md and follow it. Check whether this project is affected by CVE-2015-3405. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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