CVE-2015-7851Network attack vector

Arbitrary file overwrite via VMS path characters

Published Jan 28, 2020 · Updated Aug 6, 2024

Path traversal in NTP 4.2.x before 4.2.8p4 and 4.3.x before 4.3.77 allows remote authenticated users to overwrite OpenVMS files. The save_config function in ntpd/ntp_control.c rejects slashes but accepts OpenVMS drive and directory metacharacters, allowing a supplied filename to escape the configuration directory. Reachability requires remote configuration, a permitted source address, and either the configuration password or disabled authentication; writes retain ntpd's access rights.

CVSS severity6.5
Medium
EPSS probability3.94%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Path traversal in NTP 4.2.x before 4.2.8p4 and 4.3.x before 4.3.77 allows remote authenticated users to overwrite OpenVMS files. The save_config function in ntpd/ntp_control.c rejects slashes but accepts OpenVMS drive and directory metacharacters, allowing a supplied filename to escape the configuration directory. Reachability requires remote configuration, a permitted source address, and either the configuration password or disabled authentication; writes retain ntpd's access rights.

The record

CVE
CVE-2015-7851
Published
Jan 28, 2020
Updated
Aug 6, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 28, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 6, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.2Network Time FoundationAV:N/AC:H/Au:M/C:N/I:P/A:C
4.0NIST NVDAV:N/AC:M/Au:S/C:N/I:P/A:N
6.5UbuntuCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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