LinuxOperating system · Oracle
CVE-2015-7692
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 · uneditedThe crypto_xmit function in ntpd in NTP 4.2.x before 4.2.8p4, and 4.3.x before 4.3.77 allows remote attackers to cause a denial of service (crash). NOTE: This vulnerability exists due to an incomplete fix for CVE-2014-9750.
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 confidenceA denial of service vulnerability exists in the crypto_xmit function of ntpd in NTP versions 4.2.x before 4.2.8p4 and 4.3.x before 4.3.77. Remote attackers can trigger a crash in the NTP daemon via specially crafted packets, causing time synchronization services to become unavailable.
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
LinuxOperating system
= 6
Debian LinuxOperating system
= 7.0= 8.0= 9.0
Enterprise Linux DesktopOperating system
= 6.0= 7.0
Enterprise Linux ServerOperating system
= 6.0= 7.0
Enterprise Linux Server AusOperating system
= 7.3= 7.4= 7.6= 7.7
Enterprise Linux Server EusOperating system
= 7.3= 7.4= 7.5= 7.6= 7.7
Enterprise Linux Server TusOperating system
= 7.3= 7.6= 7.7
Enterprise Linux WorkstationOperating system
= 6.0= 7.0CVSS 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
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/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.
-
Check installed NTP versionRun 'ntpd --version' or 'ntpdc -version' or 'rpm -q ntp' to determine the installed NTP versionAffected if Version is 4.2.x before 4.2.8p4 OR version 4.3.x before 4.3.77
-
Verify NTP service is runningRun 'systemctl status ntpd' or 'service ntpd status' to check if the ntpd daemon is activeAffected if NTP daemon is running and vulnerable version is installed
-
Confirm network exposureRun 'netstat -ulnp | grep 123' or 'ss -ulnp | grep 123' to verify ntpd is listening on UDP port 123Affected if ntpd is listening on UDP 123 and vulnerable version is installed - this makes the DoS exploitable remotely
-
Check NTP operational statusRun 'ntpdc -c peers' or 'ntpq -p' to confirm NTP is actively syncing or accepting associationsAffected if NTP is operational and vulnerable version is installed - attacker can disrupt time sync service
A system is affected if it runs a vulnerable NTP version (4.2.x before 4.2.8p4 or 4.3.x before 4.3.77) with ntpd listening on the network, allowing remote attackers to crash the daemon and disrupt time synchronization.
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 dataUpgrade NTP to version 4.2.8p4 or 4.3.77 or later to address this vulnerability. If immediate patching is not possible, consider restricting NTP access to trusted sources via firewall rules or authentication.
Fix this in Linux
Scoped from the published advisory
- Consultation2.0 h
- Implementation2.0 h
- Testing3.0 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 $2,224.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2015-7692 — 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-2015-7692 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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- Version or environment caveats, and links to real fixes
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