ntpd 4.2.8 Crypto-NAK Packet Logic improper authentication

CVSS Meta Temp Score
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CTI Interest Score
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7.7$0-$5k0.00

Summaryinfo

A vulnerability labeled as critical has been found in ntpd 4.2.8. The impacted element is an unknown function of the component Crypto-NAK Packet Handler. Executing a manipulation can lead to improper authentication (Logic). The identification of this vulnerability is CVE-2015-7871. There is no exploit available. The affected component should be upgraded.

Detailsinfo

A vulnerability has been found in ntpd 4.2.8 (Network Management Software) and classified as critical. This vulnerability affects an unknown part of the component Crypto-NAK Packet Handler. The manipulation with an unknown input leads to a improper authentication vulnerability (Logic). The CWE definition for the vulnerability is CWE-287. When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct. As an impact it is known to affect integrity, and availability. CVE summarizes:

Crypto-NAK packets in ntpd in NTP 4.2.x before 4.2.8p4, and 4.3.x before 4.3.77 allows remote attackers to bypass authentication.

The weakness was shared 10/21/2015 with Cisco as cisco-sa-20151021-ntp as confirmed advisory (Website). The advisory is shared for download at tools.cisco.com. This vulnerability was named CVE-2015-7871 since 10/19/2015. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. There are neither technical details nor an exploit publicly available.

It is declared as highly functional. As 0-day the estimated underground price was around $5k-$25k. The vulnerability scanner Nessus provides a plugin with the ID 86638 (Amazon Linux AMI : ntp (ALAS-2015-607)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Amazon Linux Local Security Checks. The commercial vulnerability scanner Qualys is able to test this issue with plugin 38684 (Network Time Protocol Multiple Security Vulnerabilities (ntp-4.2.8p4)).

Upgrading to version 4.2.8p4 eliminates this vulnerability. A possible mitigation has been published immediately after the disclosure of the vulnerability. Furthermore it is possible to detect and prevent this kind of attack with TippingPoint and the filter 21764.

The vulnerability is also documented in the databases at X-Force (107436), Tenable (86638), SecurityFocus (BID 77287†) and Vulnerability Center (SBV-53951†). Additional details are provided at talosintel.com. The entries VDB-78845, VDB-78846, VDB-78847 and VDB-78848 are related to this item. Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

Name

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.1
VulDB Meta Temp Score: 7.7

VulDB Base Score: 6.5
VulDB Temp Score: 5.7
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 9.8
NVD Vector: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Name: Logic
Class: Improper authentication / Logic
CWE: CWE-287
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Status: Highly functional

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 86638
Nessus Name: Amazon Linux AMI : ntp (ALAS-2015-607)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍

OpenVAS ID: 14611
OpenVAS Name: Amazon Linux Local Check: alas-2015-607
OpenVAS File: 🔍
OpenVAS Family: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

MetaSploit ID: ntp_nak_to_the_future.rb
MetaSploit Name: NTP NAK to the Future
MetaSploit File: 🔍

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

Reaction Time: 🔍
0-Day Time: 🔍
Exposure Time: 🔍

Upgrade: ntpd 4.2.8p4
TippingPoint: 🔍

McAfee IPS: 🔍
McAfee IPS Version: 🔍

Timelineinfo

10/19/2015 🔍
10/21/2015 +2 days 🔍
10/21/2015 +0 days 🔍
10/21/2015 +0 days 🔍
10/21/2015 +0 days 🔍
10/23/2015 +2 days 🔍
10/23/2015 +0 days 🔍
08/07/2017 +654 days 🔍
06/24/2022 +1782 days 🔍

Sourcesinfo

Advisory: cisco-sa-20151021-ntp
Organization: Cisco
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2015-7871 (🔍)
GCVE (CVE): GCVE-0-2015-7871
GCVE (VulDB): GCVE-100-78844

OVAL: 🔍

X-Force: 107436 - Network Time Protocol crypto-NAK security bypass
SecurityFocus: 77287 - Network Time Protocol CVE-2015-7871 Authentication Bypass Vulnerability
SecurityTracker: 1033951
Vulnerability Center: 53951 - NTP before 4.2.8p4 Remote Restrictions Bypass and DoS via Crypto-NAK Packets, Medium

Misc.: 🔍
See also: 🔍

Entryinfo

Created: 10/23/2015 10:01
Updated: 06/24/2022 20:59
Changes: 10/23/2015 10:01 (90), 02/20/2018 10:28 (7), 06/24/2022 20:52 (4), 06/24/2022 20:59 (1)
Complete: 🔍
Cache ID: 216::103

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