LinuxOperating system · Oracle
CVE-2015-7701
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 · uneditedMemory leak in the CRYPTO_ASSOC 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 (memory consumption).
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 memory leak exists in the CRYPTO_ASSOC function of ntpd in NTP versions 4.2.x before 4.2.8p4 and 4.3.x before 4.3.77. Remote attackers can exploit this by sending specially crafted packets to trigger the leak, causing memory consumption that leads to denial of service.
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.
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Identify ntpd versionRun `ntpd --version` or `ntpdc -version` or check the package version with `rpm -q ntp` (RHEL) or `dpkg -l ntp` (Debian)Affected if Version is 4.2.x before 4.2.8p4, or 4.3.x before 4.3.77, or if the version cannot be determined and the system is one of the listed affected distributions
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Check for memory consumptionMonitor ntpd process memory usage over time with `ps aux | grep ntpd` or check system memory with `free -m`. Compare memory at intervals to detect growthAffected if ntpd process shows continuously increasing memory consumption without leveling off
The system is affected if ntpd is running with a vulnerable version (pre-4.2.8p4 or pre-4.3.77), is network-accessible, and has cryptographic authentication enabled or is exposed to unauthenticated crypto association requests.
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 later (4.3.x series: 4.3.77 or later) to remediate the memory leak vulnerability. If immediate patching is not possible, consider restricting network access to NTP ports or implementing rate limiting on NTP communications.
Fix this in Linux
Scoped from the published advisory
- Consultation2.0 h
- Implementation3.0 h
- Testing2.0 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 $2,272.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2015-7701 — 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-2015-7701 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
- No weaponised exploit code, or anything meant to cause harm
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