dbcve.org
XenserverApplication · Citrix

CVE-2015-7705

CRITICAL · 9.8 CVSS v3.1 Published 2017-08-07
Fix available
A fix is available. Upgrade to 4.2.8 / 4.3.77 or later.
See remediation →
100/100
Remediation priority · Urgent
Public exploit Remotely reachable No privileges Zero-click

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 · unedited
The rate limiting feature in NTP 4.x before 4.2.8p4 and 4.3.x before 4.3.77 allows remote attackers to have unspecified impact via a large number of crafted requests.

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
How this class of weakness works · CWE-20

The application accepts input without confirming it is well-formed or within expected bounds, so malformed data can push the program into states its author never anticipated. Attackers probe these gaps to trigger crashes, bypass logic, or feed tainted values into more dangerous operations downstream. Remediating it well means validating and normalising every input at the boundary against a strict allow-list — not merely filtering known-bad values.

General guidance for the improper input validation class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →

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
XenserverApplication
Affected:= 6.0.2= 6.2.0= 6.5= 7.0
NtpApplication
Affected:>= 4.2.0, < 4.2.8>= 4.3.0, < 4.3.77= 4.2.8
Oncommand Performance ManagerApplication
Affected:all versions
Oncommand Unified ManagerApplication
Affected:all versions
Clustered Data OntapOperating system
Affected:all versions
Data OntapOperating system
Affected:all versions
Tim 4r Ie FirmwareOperating system
Affected:all versions
Tim 4r Ie Dnp3 FirmwareOperating system
Affected:all versions

CVSS 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
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

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.

dbcve · scoped
Upgrade available Upgrade to 4.2.8 / 4.3.77 or later
Fixed in 4.2.84.3.77
Recommended fix High confidence

NTP 4.2.8p4 or later, or NTP 4.3.77 or later

  1. 1. Identify the NTP version currently installed: 'ntpd --version' or 'ntpdc -version'
  2. 2. For Linux/Unix systems: Download NTP 4.2.8p4 or later (or 4.3.77+) from the official NTP website (ntp.org) or your distribution's package repository
  3. 3. Stop the NTP service: 'systemctl stop ntpd' or 'service ntpd stop'
  4. 4. Backup the current NTP configuration: 'cp /etc/ntp.conf /etc/ntp.conf.backup'
  5. 5. Install the fixed NTP version using your package manager or compile from source
  6. 6. Verify the installation: 'ntpd --version' should show 4.2.8p4 or higher, or 4.3.77 or higher
  7. 7. Start the NTP service: 'systemctl start ntpd' or 'service ntpd start'
  8. 8. For Xenserver, Oncommand, Data Ontap, and TIM firmware products: Apply vendor-specific patches or upgrade to vendor-provided patched versions that include the fixed NTP version
Caveat NTP upgrades are generally low risk but test in non-production environments first; some custom configuration files may need review after upgrade

Generated from the published advisory — verify against the referenced sources before acting.

We can perform the upgrade in your staging environment and verify nothing breaks — typical engagement from $2,300. Get the upgrade done

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2015-7705 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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