How severe is CVE-2015-7851?

CVE-2015-7851 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.

Is CVE-2015-7851 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (89th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2015-7851?

CVE-2015-7851 primarily affects Ntp. In total, 17 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2015-7851?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2015-7851 published?

CVE-2015-7851 was published on 2020-01-28 and last updated on 2026-06-17.

CVE-2015-7851

CVE-2015-7851 is a medium-severity vulnerability in Ntp with a CVSS 3.x base score of 6.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-22.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
CVSS v2: 3.5
EPSS exploit prediction: 4% (89th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-22
Affected product: Ntp
Published: 2020-01-28
Last modified: 2026-06-17

Description

Directory traversal vulnerability in the save_config function in ntpd in ntp_control.c in NTP before 4.2.8p4, when used on systems that do not use '\' or '/' characters for directory separation such as OpenVMS, allows remote authenticated users to overwrite arbitrary files.

Frequently asked questions

What is CVE-2015-7851?: Directory traversal vulnerability in the save_config function in ntpd in ntp_control.c in NTP before 4.2.8p4, when used on systems that do not use '\' or '/' characters for directory separation such as OpenVMS, allows remote authenticated users to overwrite arbitrary files.
How severe is CVE-2015-7851?: CVE-2015-7851 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.
Is CVE-2015-7851 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (89th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2015-7851?: CVE-2015-7851 primarily affects Ntp. In total, 17 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2015-7851?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2015-7851 published?: CVE-2015-7851 was published on 2020-01-28 and last updated on 2026-06-17.

References

Affected products (17)

cpe:2.3:a:ntp:ntp:*:*:*:*:*:*:*:*
cpe:2.3:a:ntp:ntp:4.2.8:p1:*:*:*:*:*:*
cpe:2.3:a:ntp:ntp:4.2.8:p1-beta1:*:*:*:*:*:*
cpe:2.3:a:ntp:ntp:4.2.8:p1-beta2:*:*:*:*:*:*
cpe:2.3:a:ntp:ntp:4.2.8:p1-beta3:*:*:*:*:*:*
cpe:2.3:a:ntp:ntp:4.2.8:p1-beta4:*:*:*:*:*:*
cpe:2.3:a:ntp:ntp:4.2.8:p1-beta5:*:*:*:*:*:*
cpe:2.3:a:ntp:ntp:4.2.8:p1-rc1:*:*:*:*:*:*
cpe:2.3:a:ntp:ntp:4.2.8:p1-rc2:*:*:*:*:*:*
cpe:2.3:a:ntp:ntp:4.2.8:p2:*:*:*:*:*:*
cpe:2.3:a:ntp:ntp:4.2.8:p2-rc1:*:*:*:*:*:*
cpe:2.3:a:ntp:ntp:4.2.8:p2-rc2:*:*:*:*:*:*
cpe:2.3:a:ntp:ntp:4.2.8:p2-rc3:*:*:*:*:*:*
cpe:2.3:a:ntp:ntp:4.2.8:p3:*:*:*:*:*:*
cpe:2.3:a:ntp:ntp:4.2.8:p3-rc1:*:*:*:*:*:*
cpe:2.3:a:ntp:ntp:4.2.8:p3-rc2:*:*:*:*:*:*
cpe:2.3:a:ntp:ntp:4.2.8:p3-rc3:*:*:*:*:*:*

More vulnerabilities in Ntp

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CVE-2015-7853 — Critical (CVSS 9.8): The datalen parameter in the refclock driver in NTP 4.2.x before 4.2.8p4, and 4.3.x before 4.3.77 allows remote…
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CVE-2015-7854 — High (CVSS 8.8): Buffer overflow in the password management functionality in NTP 4.2.x before 4.2.8p4, and 4.3.x before 4.3.77 allows…

All CVEs affecting Ntp →

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Threat intelligence

Threat-intel indicators referencing this CVE:

197.248.207.139 (ipv4-addr)
135.129.128.247 (ipv4-addr)
119.201.59.224 (ipv4-addr)
42.200.60.186 (ipv4-addr)
223.197.153.135 (ipv4-addr)
125.212.244.35 (ipv4-addr)
202.29.220.126 (ipv4-addr)
93.42.227.251 (ipv4-addr)