ntpd 4.2.8 decodenetnum input validation

CVSS Meta Temp Score
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CTI Interest Score
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5.6$0-$5k0.00

Summaryinfo

A vulnerability categorized as problematic has been discovered in ntpd 4.2.8. This affects the function decodenetnum. Executing a manipulation can lead to input validation. This vulnerability is handled as CVE-2015-7855. Additionally, an exploit exists. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability was found in ntpd 4.2.8 (Network Management Software). It has been declared as problematic. This vulnerability affects the function decodenetnum. The manipulation with an unknown input leads to a input validation vulnerability. The CWE definition for the vulnerability is CWE-20. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. As an impact it is known to affect availability. CVE summarizes:

The decodenetnum function in ntpd in NTP 4.2.x before 4.2.8p4, and 4.3.x before 4.3.77 allows remote attackers to cause a denial of service (assertion failure) via a 6 or mode 7 packet containing a long data value.

The weakness was released 10/21/2015 as cisco-sa-20151021-ntp as confirmed advisory (Website). The advisory is shared for download at tools.cisco.com. This vulnerability was named CVE-2015-7855 since 10/16/2015. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. Technical details and also a public exploit are known.

A public exploit has been developed in Python. It is possible to download the exploit at securityfocus.com. It is declared as proof-of-concept. As 0-day the estimated underground price was around $5k-$25k. The vulnerability scanner Nessus provides a plugin with the ID 88055 (AIX 6.1 TL 9 : ntp (IV79942) (deprecated)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family AIX 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 21633.

The vulnerability is also documented in the databases at X-Force (107448), Exploit-DB (40840), Tenable (88055), SecurityFocus (BID 77283†) and Vulnerability Center (SBV-53950†). Entries connected to this vulnerability are available at VDB-78844, VDB-78845, VDB-78846 and VDB-78847. VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Type

Name

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.9
VulDB Meta Temp Score: 5.6

VulDB Base Score: 5.3
VulDB Temp Score: 4.8
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 6.5
NVD Vector: 🔍

CVSSv2info

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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Input validation
CWE: CWE-20
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Access: Public
Status: Proof-of-Concept
Programming Language: 🔍
Download: 🔍

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 88055
Nessus Name: AIX 6.1 TL 9 : ntp (IV79942) (deprecated)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍

OpenVAS ID: 800407
OpenVAS Name: NTP.org ntp decodenetnum And loop counter underrun DoS Vulnerabilities
OpenVAS File: 🔍
OpenVAS Family: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Exploit-DB: 🔍

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: 🔍

Fortigate IPS: 🔍

Timelineinfo

10/16/2015 🔍
10/21/2015 +5 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 🔍
11/11/2024 +2653 days 🔍

Sourcesinfo

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

CVE: CVE-2015-7855 (🔍)
GCVE (CVE): GCVE-0-2015-7855
GCVE (VulDB): GCVE-100-78856

OVAL: 🔍

X-Force: 107448 - Network Time Protocol decodenetnum() denial of service
SecurityFocus: 77283 - Network Time Protocol CVE-2015-7855 Denial of Service Vulnerability
SecurityTracker: 1033951
Vulnerability Center: 53950 - NTP before 4.2.8p4 Remote Unspecified Vulnerability in the Decodenetnum() Function - CVE-2015-7855, High

scip Labs: https://www.scip.ch/en/?labs.20161013
See also: 🔍

Entryinfo

Created: 10/23/2015 10:06
Updated: 11/11/2024 20:12
Changes: 10/23/2015 10:06 (87), 02/20/2018 10:27 (10), 06/25/2022 01:28 (4), 06/25/2022 01:35 (1), 11/11/2024 20:12 (19)
Complete: 🔍
Cache ID: 216:744:103

VulDB is the best source for vulnerability data and more expert information about this specific topic.

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