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.
8.0	$0-$5k	0.00

Summaryinfo

A vulnerability has been found in Mono up to 3.12.0 and classified as critical. This vulnerability affects unknown code of the component TLS Stack. The manipulation leads to certificate validation (SSL). This vulnerability was named CVE-2015-2320. The attack can be initiated remotely. There is no exploit available. It is recommended to upgrade the affected component. Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Detailsinfo

A vulnerability, which was classified as critical, was found in Mono up to 3.12.0. This affects an unknown part of the component TLS Stack. The manipulation with an unknown input leads to a certificate validation vulnerability (SSL). CWE is classifying the issue as CWE-295. The product does not validate, or incorrectly validates, a certificate. This is going to have an impact on confidentiality, and integrity. The summary by CVE is:

The TLS stack in Mono before 3.12.1 allows remote attackers to have unspecified impact via vectors related to client-side SSLv2 fallback.

The bug was discovered 03/07/2015. The weakness was presented 01/08/2018 by Inria (oss-sec). The advisory is shared at openwall.com. This vulnerability is uniquely identified as CVE-2015-2320 since 03/17/2015. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Neither technical details nor an exploit are publicly available. MITRE ATT&CK project uses the attack technique T1587.003 for this issue.

The vulnerability was handled as a non-public zero-day exploit for at least 12 days. During that time the estimated underground price was around $0-$5k. The vulnerability scanner Nessus provides a plugin with the ID 82161 (Debian DLA-176-1 : mono security update), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Debian Local Security Checks and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 167780 (SUSE Enterprise Linux Security update for Mono (SUSE-SU-2015:0841-1)).

Upgrading to version 3.12.1 eliminates this vulnerability. A possible mitigation has been published even before and not after the disclosure of the vulnerability.

The vulnerability is also documented in the databases at Tenable (82161) and SecurityFocus (BID 73256†). See VDB-111511 and VDB-111512 for similar entries. Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Name

• Mono

Version

• 3.0
• 3.1
• 3.2
• 3.3
• 3.4
• 3.5
• 3.6
• 3.7
• 3.8
• 3.9
• 3.10
• 3.11
• 3.12.0

License

• open-source

CPE 2.3info

• 🔍
• 🔍
• 🔍

CPE 2.2info

• 🔍
• 🔍
• 🔍

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.1
VulDB Meta Temp Score: 8.0

VulDB Base Score: 6.5
VulDB Temp Score: 6.2
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 9.8
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: SSL
Class: Certificate validation / SSL
CWE: CWE-295 / CWE-287
CAPEC: 🔍
ATT&CK: 🔍

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: 82161
Nessus Name: Debian DLA-176-1 : mono security update
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

OpenVAS ID: 841810
OpenVAS Name: Ubuntu Update for mono USN-2547-1
OpenVAS File: 🔍
OpenVAS Family: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: Mono 3.12.1
Patch: github.com

Timelineinfo

03/07/2015 🔍
03/17/2015 +10 days 🔍
03/17/2015 +0 days 🔍
03/19/2015 +2 days 🔍
03/26/2015 +7 days 🔍
01/08/2018 +1019 days 🔍
01/08/2018 +0 days 🔍
01/09/2018 +1 days 🔍
01/20/2023 +1837 days 🔍

Sourcesinfo

Advisory: USN-2547-1
Researcher: Inria (Inria)
Status: Not defined
Confirmation: 🔍

CVE: CVE-2015-2320 (🔍)
GCVE (CVE): GCVE-0-2015-2320
GCVE (VulDB): GCVE-100-111513

OVAL: 🔍

SecurityFocus: 73256 - Mono SSLv2 Fallback CVE-2015-2320 Man in the Middle Security Bypass Vulnerability

See also: 🔍

Entryinfo

Created: 01/09/2018 08:18 AM
Updated: 01/20/2023 12:49 PM
Changes: 01/09/2018 08:18 AM (80), 12/20/2019 03:52 PM (2), 01/29/2021 10:29 AM (3), 01/20/2023 12:49 PM (4)
Complete: 🔍
Cache ID: 18:7F0:40

Discussion

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