Xscreensaver up to 5.33 Monitor driver/subprocs.c access control

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.
4.7	$0-$5k	0.00

Summaryinfo

A vulnerability, which was classified as problematic, has been found in Xscreensaver up to 5.33. This vulnerability affects unknown code of the file driver/subprocs.c of the component Monitor Handler. The manipulation leads to access control. This vulnerability is referenced as CVE-2015-8025. No exploit is available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability was found in Xscreensaver up to 5.33 and classified as problematic. This issue affects an unknown functionality of the file driver/subprocs.c of the component Monitor Handler. The manipulation with an unknown input leads to a access control vulnerability. Using CWE to declare the problem leads to CWE-264. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

driver/subprocs.c in XScreenSaver before 5.34 does not properly perform an internal consistency check, which allows physically proximate attackers to bypass the lock screen by hot swapping monitors.

The weakness was published 11/10/2015 (Website). It is possible to read the advisory at jwz.org. The identification of this vulnerability is CVE-2015-8025 since 10/29/2015. The exploitation is known to be difficult. Attacking locally is a requirement. No form of authentication is needed for a successful exploitation. Technical details of the vulnerability are known, but there is no available exploit. The attack technique deployed by this issue is T1068 according to MITRE ATT&CK.

The vulnerability scanner Nessus provides a plugin with the ID 86720 (Ubuntu 12.04 LTS : xscreensaver vulnerability (USN-2789-1)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Ubuntu Local Security Checks and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 175590 (Debian Security Update for xscreensaver (DSA 3438-1)).

Upgrading to version 5.34 eliminates this vulnerability. A possible mitigation has been published before and not just after the disclosure of the vulnerability.

The vulnerability is also documented in the databases at Tenable (86720) and Vulnerability Center (SBV-54451†). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Name

• Xscreensaver

Version

• 5.0
• 5.1
• 5.2
• 5.3
• 5.4
• 5.5
• 5.6
• 5.7
• 5.8
• 5.9
• 5.10
• 5.11
• 5.12
• 5.13
• 5.14
• 5.15
• 5.16
• 5.17
• 5.18
• 5.19
• 5.20
• 5.21
• 5.22
• 5.23
• 5.24
• 5.25
• 5.26
• 5.27
• 5.28
• 5.29
• 5.30
• 5.31
• 5.32
• 5.33

CPE 2.3info

• 🔍
• 🔍
• 🔍

CPE 2.2info

• 🔍
• 🔍
• 🔍

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 4.9
VulDB Meta Temp Score: 4.7

VulDB Base Score: 4.9
VulDB Temp Score: 4.7
VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Access control
CWE: CWE-264
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: No

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: 86720
Nessus Name: Ubuntu 12.04 LTS : xscreensaver vulnerability (USN-2789-1)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

OpenVAS ID: 841810
OpenVAS Name: Ubuntu Update for xscreensaver USN-2789-1
OpenVAS File: 🔍
OpenVAS Family: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: Xscreensaver 5.34

Timelineinfo

10/28/2015 🔍
10/29/2015 +1 days 🔍
11/03/2015 +5 days 🔍
11/04/2015 +1 days 🔍
11/10/2015 +6 days 🔍
11/10/2015 +0 days 🔍
11/11/2015 +1 days 🔍
11/17/2015 +6 days 🔍
11/12/2024 +3283 days 🔍

Sourcesinfo

Advisory: USN-2789-1
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2015-8025 (🔍)
GCVE (CVE): GCVE-0-2015-8025
GCVE (VulDB): GCVE-100-79115

OVAL: 🔍

SecurityTracker: 1034052
Vulnerability Center: 54451 - XScreenSaver before 5.34 Local Security Bypass in Driver/subprocs.c, Low

Entryinfo

Created: 11/11/2015 09:18
Updated: 11/12/2024 06:28
Changes: 11/11/2015 09:18 (55), 04/13/2018 08:47 (14), 06/26/2022 14:18 (4), 11/12/2024 06:28 (18)
Complete: 🔍
Cache ID: 216:5E6:103

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Discussion

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