medium
6.5
CWE
20
Advisory Published
CVE Published
Updated

CVE-2015-7855: Input Validation

First published: Thu Oct 22 2015(Updated: )

It was found that NTP's decodenetnum() would abort with an assertion failure when processing a mode 6 or mode 7 packet containing an unusually long data value where a network address was expected. This could allow an authenticated attacker to crash ntpd. External References: <a href="https://github.com/ntp-project/ntp/blob/stable/NEWS#L295">https://github.com/ntp-project/ntp/blob/stable/NEWS#L295</a> <a href="http://support.ntp.org/bin/view/Main/SecurityNotice#October_2015_NTP_Security_Vulner">http://support.ntp.org/bin/view/Main/SecurityNotice#October_2015_NTP_Security_Vulner</a>

Credit: cve@mitre.org

Affected SoftwareAffected VersionHow to fix
redhat/ntp<4.2.8
4.2.8
Siemens TIM 4R-IE
Siemens TIM 4R-IE DNP3
NTP>=4.2.0<4.2.8
NTP>=4.3.0<4.3.77
NTP=4.2.8
NTP=4.2.8-p1
NTP=4.2.8-p1-beta1
NTP=4.2.8-p1-beta2
NTP=4.2.8-p1-beta3
NTP=4.2.8-p1-beta4
NTP=4.2.8-p1-beta5
NTP=4.2.8-p1-rc1
NTP=4.2.8-p1-rc2
NTP=4.2.8-p2
NTP=4.2.8-p2-rc1
NTP=4.2.8-p2-rc2
NTP=4.2.8-p2-rc3
NTP=4.2.8-p3
NTP=4.2.8-p3-rc1
NTP=4.2.8-p3-rc2
NTP=4.2.8-p3-rc3
Debian Linux=7.0
Debian Linux=8.0
Debian Linux=9.0
NetApp OnCommand Balance
NetApp OnCommand Performance Manager
NetApp OnCommand Unified Manager
IBM Data ONTAP
IBM Data ONTAP
Siemens TIM 4R-IE DNP3
siemens SIMATIC TIM 4R-IE
Siemens TIM 4R-IE
Siemens TIM 4R-IE

Remedy

http://support.ntp.org/bin/view/Main/NtpBug2922

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Reference Links

Parent vulnerabilities

(Appears in the following advisories)

Frequently Asked Questions

  • What is the severity of CVE-2015-7855?

    CVE-2015-7855 has a severity level that could potentially allow an authenticated attacker to crash the ntpd service.

  • How do I fix CVE-2015-7855?

    To address CVE-2015-7855, upgrade NTP to version 4.2.8 or later.

  • Which software is affected by CVE-2015-7855?

    CVE-2015-7855 affects versions of NTP from 4.2.0 to 4.2.8 and other specific Siemens products.

  • What is the impact of exploiting CVE-2015-7855?

    Exploiting CVE-2015-7855 could lead to a denial of service by crashing the ntpd process.

  • Is CVE-2015-7855 easy to exploit?

    CVE-2015-7855 requires authentication, making it less accessible for unauthenticated attackers but still a risk.

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