medium
5.3
CWE
20
Advisory Published
Updated

CVE-2016-2517: Input Validation

First published: Mon Jan 30 2017(Updated: )

NTP before 4.2.8p7 and 4.3.x before 4.3.92 allows remote attackers to cause a denial of service (prevent subsequent authentication) by leveraging knowledge of the controlkey or requestkey and sending a crafted packet to ntpd, which changes the value of trustedkey, controlkey, or requestkey. NOTE: this vulnerability exists because of a CVE-2016-2516 regression.

Credit: cve@mitre.org

Affected SoftwareAffected VersionHow to fix
NTP ntp<=4.2.8
NTP ntp=4.3.0
NTP ntp=4.3.1
NTP ntp=4.3.2
NTP ntp=4.3.3
NTP ntp=4.3.4
NTP ntp=4.3.5
NTP ntp=4.3.6
NTP ntp=4.3.7
NTP ntp=4.3.8
NTP ntp=4.3.9
NTP ntp=4.3.10
NTP ntp=4.3.11
NTP ntp=4.3.12
NTP ntp=4.3.13
NTP ntp=4.3.14
NTP ntp=4.3.15
NTP ntp=4.3.16
NTP ntp=4.3.17
NTP ntp=4.3.18
NTP ntp=4.3.19
NTP ntp=4.3.20
NTP ntp=4.3.21
NTP ntp=4.3.22
NTP ntp=4.3.23
NTP ntp=4.3.24
NTP ntp=4.3.25
NTP ntp=4.3.26
NTP ntp=4.3.27
NTP ntp=4.3.28
NTP ntp=4.3.29
NTP ntp=4.3.30
NTP ntp=4.3.31
NTP ntp=4.3.32
NTP ntp=4.3.33
NTP ntp=4.3.34
NTP ntp=4.3.35
NTP ntp=4.3.36
NTP ntp=4.3.37
NTP ntp=4.3.38
NTP ntp=4.3.39
NTP ntp=4.3.40
NTP ntp=4.3.41
NTP ntp=4.3.42
NTP ntp=4.3.43
NTP ntp=4.3.44
NTP ntp=4.3.45
NTP ntp=4.3.46
NTP ntp=4.3.47
NTP ntp=4.3.48
NTP ntp=4.3.49
NTP ntp=4.3.50
NTP ntp=4.3.51
NTP ntp=4.3.52
NTP ntp=4.3.53
NTP ntp=4.3.54
NTP ntp=4.3.55
NTP ntp=4.3.56
NTP ntp=4.3.57
NTP ntp=4.3.58
NTP ntp=4.3.59
NTP ntp=4.3.60
NTP ntp=4.3.61
NTP ntp=4.3.62
NTP ntp=4.3.63
NTP ntp=4.3.64
NTP ntp=4.3.65
NTP ntp=4.3.66
NTP ntp=4.3.67
NTP ntp=4.3.68
NTP ntp=4.3.69
NTP ntp=4.3.70
NTP ntp=4.3.71
NTP ntp=4.3.72
NTP ntp=4.3.73
NTP ntp=4.3.74
NTP ntp=4.3.75
NTP ntp=4.3.76
NTP ntp=4.3.77
NTP ntp=4.3.78
NTP ntp=4.3.79
NTP ntp=4.3.80
NTP ntp=4.3.81
NTP ntp=4.3.82
NTP ntp=4.3.83
NTP ntp=4.3.84
NTP ntp=4.3.85
NTP ntp=4.3.86
NTP ntp=4.3.87
NTP ntp=4.3.88
NTP ntp=4.3.89
NTP ntp=4.3.90
NTP ntp=4.3.91

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Reference Links

Frequently Asked Questions

  • What is the severity of CVE-2016-2517?

    CVE-2016-2517 has a medium severity rating due to its potential for causing denial of service.

  • How do I fix CVE-2016-2517?

    To fix CVE-2016-2517, update to NTP version 4.2.8p7 or later for 4.2.x, or version 4.3.92 or later for 4.3.x.

  • What versions of NTP are affected by CVE-2016-2517?

    CVE-2016-2517 affects NTP versions prior to 4.2.8p7 and 4.3.x before 4.3.92.

  • What type of attack does CVE-2016-2517 enable?

    CVE-2016-2517 enables remote attackers to cause a denial of service by modifying trusted keys through crafted packets.

  • Is CVE-2016-2517 exploitable remotely?

    Yes, CVE-2016-2517 is exploitable remotely as it involves sending crafted packets to the NTP daemon.

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