VDB-123343 · CVE-2018-15919 · BID 105163

OpenSSH up to 7.8 GSS2 auth-gss2.c Username information disclosure

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
5.2	$5k-$25k	0.04

A vulnerability was found in OpenSSH up to 7.8 (Connectivity Software). It has been declared as problematic. Affected by this vulnerability is an unknown part of the file auth-gss2.c of the component GSS2. The manipulation with an unknown input leads to a information disclosure vulnerability (Username). The CWE definition for the vulnerability is CWE-200. The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information. As an impact it is known to affect confidentiality. The summary by CVE is:

Remotely observable behaviour in auth-gss2.c in OpenSSH through 7.8 could be used by remote attackers to detect existence of users on a target system when GSS2 is in use. NOTE: the discoverer states 'We understand that the OpenSSH developers do not want to treat such a username enumeration (or "oracle") as a vulnerability.'

The bug was discovered 08/27/2018. The weakness was presented 08/28/2018 with Qualys (Website). It is possible to read the advisory at seclists.org. This vulnerability is known as CVE-2018-15919 since 08/28/2018. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 03/19/2020). The attack technique deployed by this issue is T1592 according to MITRE ATT&CK.

The vulnerability was handled as a non-public zero-day exploit for at least 1 days. During that time the estimated underground price was around $5k-$25k. The vulnerability scanner Nessus provides a plugin with the ID 118498 (SUSE SLES11 Security Update : openssh (SUSE-SU-2018:3540-1)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family SuSE Local Security Checks and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 171714 (SUSE Enterprise Linux Security Update for openssh (SUSE-SU-2018:3781-1)).

Proper firewalling of is able to address this issue. A possible mitigation has been published 3 months after the disclosure of the vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (118498).

Productinfo

Type

Connectivity Software

Name

OpenSSH

Version

License

open-source

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB CVSS-B Score: 🔍
VulDB CVSS-BT Score: 🔍
VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.3
VulDB Meta Temp Score: 5.2

VulDB Base Score: 5.3
VulDB Temp Score: 5.2
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 5.3
NVD Vector: 🔍

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
unlock	unlock	unlock	unlock	unlock	unlock
unlock	unlock	unlock	unlock	unlock	unlock
unlock	unlock	unlock	unlock	unlock	unlock

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

NVD Base Score: 🔍

Exploitinginfo

Name: Username
Class: Information disclosure / Username
CWE: CWE-200 / CWE-284 / CWE-266
ATT&CK: T1592

Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-Day	unlock	unlock	unlock	unlock
Today	unlock	unlock	unlock	unlock

Nessus ID: 118498
Nessus Name: SUSE SLES11 Security Update : openssh (SUSE-SU-2018:3540-1)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Firewall
Status: 🔍

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

Timelineinfo

08/27/2018 🔍
08/27/2018 +0 days 🔍
08/28/2018 +0 days 🔍
08/28/2018 +0 days 🔍
08/28/2018 +0 days 🔍
08/29/2018 +1 days 🔍
10/28/2018 +60 days 🔍
10/30/2018 +2 days 🔍
03/19/2020 +506 days 🔍

Sourcesinfo

Advisory: seclists.org
Organization: Qualys
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2018-15919 (🔍)
SecurityFocus: 105163 - OpenSSH CVE-2018-15919 User Enumeration Vulnerability

Entryinfo

Created: 08/29/2018 08:32
Updated: 03/19/2020 07:18
Changes: 08/29/2018 08:32 (76), 03/19/2020 07:18 (6)
Complete: 🔍