GNU C Library 2.16 File System pt_chown Crafted File System access control

CVSS Meta Temp Score
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CTI Interest Score
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4.2$0-$5k0.00

Summaryinfo

A vulnerability classified as problematic has been found in GNU C Library 2.16. Affected by this issue is the function pt_chown of the component File System. The manipulation as part of Crafted File System leads to access control. This vulnerability is listed as CVE-2013-2207. There is no available exploit. It is recommended to apply a patch to fix this issue.

Detailsinfo

A vulnerability was found in GNU C Library 2.16 (Software Library). It has been rated as problematic. This issue affects the function pt_chown of the component File System. The manipulation as part of a Crafted File System leads to a access control vulnerability. Using CWE to declare the problem leads to CWE-264. Impacted is confidentiality, and integrity. The summary by CVE is:

pt_chown in GNU C Library (aka glibc or libc6) before 2.18 does not properly check permissions for tty files, which allows local users to change the permission on the files and obtain access to arbitrary pseudo-terminals by leveraging a FUSE file system.

The issue has been introduced in 06/30/2012. The weakness was presented 07/16/2013 by Martin Carpenter with Citco as BZ #15755 as confirmed mailinglist post (Website). It is possible to read the advisory at sourceware.org. The identification of this vulnerability is CVE-2013-2207 since 02/19/2013. Attacking locally is a requirement. Required for exploitation is a simple authentication. 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 advisory points out:

Using the setuid installed pt_chown and a weak check on whether a file descriptor is a tty, an attacker could fake a pty check using FUSE and trick pt_chown to grant ownership of a pty descriptor that the current user does not own. It cannot access /dev/pts/ptmx however.

The vulnerability was handled as a non-public zero-day exploit for at least 381 days. During that time the estimated underground price was around $0-$5k. The vulnerability scanner Nessus provides a plugin with the ID 69784 (Fedora 18 : glibc-2.16-34.fc18 (2013-15072)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Fedora Local Security Checks. The commercial vulnerability scanner Qualys is able to test this issue with plugin 196484 (Ubuntu Security Notification for Eglibc, Glibc Vulnerabilities (USN-2985-1)).

Applying the patch BZ #15755 is able to eliminate this problem. A possible mitigation has been published 3 days after the disclosure of the vulnerability.

The vulnerability is also documented in the databases at X-Force (86914), Tenable (69784), SecurityFocus (BID 61960†), OSVDB (98105†) and Secunia (SA55113†). See VDB-9979, VDB-10293, VDB-10294 and VDB-10609 for similar entries. If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 4.4
VulDB Meta Temp Score: 4.2

VulDB Base Score: 4.4
VulDB Temp Score: 4.2
VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv2info

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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: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 69784
Nessus Name: Fedora 18 : glibc-2.16-34.fc18 (2013-15072)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Port: 🔍

OpenVAS ID: 866841
OpenVAS Name: Fedora Update for glibc FEDORA-2013-15053
OpenVAS File: 🔍
OpenVAS Family: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Patch
Status: 🔍

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

Patch: BZ #15755

Timelineinfo

06/30/2012 🔍
02/19/2013 +234 days 🔍
06/20/2013 +121 days 🔍
06/20/2013 +0 days 🔍
07/16/2013 +26 days 🔍
07/19/2013 +3 days 🔍
09/05/2013 +48 days 🔍
10/01/2013 +26 days 🔍
10/01/2013 +0 days 🔍
10/07/2013 +6 days 🔍
10/09/2013 +2 days 🔍
05/26/2021 +2786 days 🔍

Sourcesinfo

Vendor: gnu.org

Advisory: BZ #15755
Researcher: Martin Carpenter
Organization: Citco
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2013-2207 (🔍)
GCVE (CVE): GCVE-0-2013-2207
GCVE (VulDB): GCVE-100-10583
X-Force: 86914
SecurityFocus: 61960
Secunia: 55113 - SUSE update for glibc, Less Critical
OSVDB: 98105
Vulnerability Center: 41701 - GNU C Library glibc 2.16 Local Security Bypass Vulnerability via pt_chown(), Low

See also: 🔍

Entryinfo

Created: 10/07/2013 17:57
Updated: 05/26/2021 09:31
Changes: 10/07/2013 17:57 (57), 05/12/2017 10:41 (35), 05/26/2021 09:31 (3)
Complete: 🔍
Cache ID: 216:3BB:103

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