FedoraOperating system · Fedoraproject
CVE-2015-5146
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedntpd in ntp before 4.2.8p3 with remote configuration enabled allows remote authenticated users with knowledge of the configuration password and access to a computer entrusted to perform remote configuration to cause a denial of service (service crash) via a NULL byte in a crafted configuration directive packet.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidencentpd before version 4.2.8p3 contains a denial-of-service vulnerability when remote configuration is enabled. An authenticated remote attacker with knowledge of the configuration password can send a crafted configuration directive packet containing a NULL byte, causing the ntpd service to crash.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
FedoraOperating system
= 21= 22= 23
Debian LinuxOperating system
= 7.0= 8.0<= 4.2.8CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- High
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.0/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Check installed ntpd versionRun 'ntpd --version' or 'ntpq -c version' to retrieve the ntpd version number, or use package management commands such as 'rpm -q ntp' or 'dpkg -l ntp'Affected if Version is lower than 4.2.8p3 (including all 4.2.8 versions without the 'p3' patch level)
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Verify if remote configuration is enabledInspect the ntpd configuration file (commonly /etc/ntp.conf) for the directive 'enable mode7' or check the ntpd command-line arguments for '-M' flag. Also check for any 'restrict ... noquery' restrictions that may limit mode7 accessAffected if Remote configuration (mode 7) is explicitly enabled via 'enable mode7' in the config file or '-M' on the command line
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Check for configuration password in ntpdSearch the ntpd configuration file for 'keys' or 'trustedkey' directives that indicate remote configuration authentication is configured. Also check for any 'requestkey' or 'controlkey' entriesAffected if A configuration password/key is defined in ntpd.conf, indicating remote configuration functionality is present
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Confirm ntpd is running and accepting mode 7 packetsUse 'netstat -anp | grep 123' or 'ss -anp | grep 123' to verify ntpd is listening on UDP port 123. A successful mode 7 connection would require network access to this portAffected if Ntpd is running and accessible on the network with remote configuration enabled on vulnerable versions
Your environment is affected if ntpd version is below 4.2.8p3 AND remote configuration (mode 7) is enabled, regardless of whether a configuration password is set.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataDisable remote configuration if not required, or update ntpd to version 4.2.8p3 or later. If remote configuration must remain enabled, ensure strong configuration passwords and restrict network access to trusted systems only.
Fix this in Fedora
Scoped from the published advisory
- Consultation1.0 h
- Implementation2.0 h
- Testing1.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,424.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2015-5146 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2015-5146 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
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