VDB-8481 · CVE-2013-1956 · BID 59554

Linux Kernel up to 3.8.5 Authentication fs/namespace.c create_user_ns access control

CVSS Meta Temp Score
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CTI Interest Score
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4.6$0-$5k0.00

Summaryinfo

A vulnerability marked as problematic has been reported in Linux Kernel up to 3.8.5. Affected by this vulnerability is the function create_user_ns of the file fs/namespace.c of the component Authentication Handler. Performing a manipulation results in access control. This vulnerability is identified as CVE-2013-1956. Additionally, an exploit exists. It is suggested to install a patch to address this issue.

Detailsinfo

A vulnerability, which was classified as problematic, was found in Linux Kernel up to 3.8.5 (Operating System). This affects the function create_user_ns of the file fs/namespace.c of the component Authentication Handler. The manipulation with an unknown input leads to a access control vulnerability. CWE is classifying the issue as CWE-264. This is going to have an impact on confidentiality, and integrity. The summary by CVE is:

The create_user_ns function in kernel/user_namespace.c in the Linux kernel before 3.8.6 does not check whether a chroot directory exists that differs from the namespace root directory, which allows local users to bypass intended filesystem restrictions via a crafted clone system call.

The weakness was released 03/27/2013 by Andy Lutomirski as not defined mailinglist post (oss-sec). The advisory is shared at openwall.com. This vulnerability is uniquely identified as CVE-2013-1956 since 02/19/2013. The exploitability is told to be easy. An attack has to be approached locally. No form of authentication is needed for exploitation. Technical details and a public exploit are known. MITRE ATT&CK project uses the attack technique T1068 for this issue.

After 3 weeks, there has been an exploit disclosed. It is declared as proof-of-concept. We expect the 0-day to have been worth approximately $25k-$100k.

Applying the patch 3151527ee007b73a0ebd296010f1c0454a919c7d is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. A possible mitigation has been published immediately after the disclosure of the vulnerability.

The vulnerability is also documented in the databases at SecurityFocus (BID 59554†), OSVDB (92593†) and Vulnerability Center (SBV-39390†). Entries connected to this vulnerability are available at VDB-8479 and VDB-8480. Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.1
VulDB Meta Temp Score: 4.6

VulDB Base Score: 5.1
VulDB Temp Score: 4.6
VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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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: 🔍
Access: Public
Status: Proof-of-Concept

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Patch
Status: 🔍

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

Patch: 3151527ee007b73a0ebd296010f1c0454a919c7d

Timelineinfo

02/19/2013 🔍
03/27/2013 +36 days 🔍
03/27/2013 +0 days 🔍
04/13/2013 +17 days 🔍
04/16/2013 +3 days 🔍
04/23/2013 +7 days 🔍
04/24/2013 +1 days 🔍
04/29/2013 +5 days 🔍
04/30/2013 +1 days 🔍
04/28/2017 +1459 days 🔍

Sourcesinfo

Vendor: kernel.org

Advisory: openwall.com
Researcher: Andy Lutomirski
Status: Not defined
Confirmation: 🔍

CVE: CVE-2013-1956 (🔍)
GCVE (CVE): GCVE-0-2013-1956
GCVE (VulDB): GCVE-100-8481
SecurityFocus: 59554 - Linux Kernel 'create_user_ns()' Function CVE-2013-1956 Local Security Bypass Vulnerability
OSVDB: 92593
Vulnerability Center: 39390 - Linux Kernel 3.8.x \x27create_user_ns()\x27 Allows Local Bypass of the File System Restrictions via a Crafted Clone System Call., High

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

Entryinfo

Created: 04/23/2013 12:27
Updated: 04/28/2017 10:06
Changes: 04/23/2013 12:27 (73), 04/28/2017 10:06 (2)
Complete: 🔍
Committer: olku
Cache ID: 216:B6B:103

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