policycoreutils 2.5-11 on SELinux Filesystem link following

CVSS Meta Temp Score
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CTI Interest Score
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4.7$0-$5k0.00

Summaryinfo

A vulnerability described as problematic has been identified in policycoreutils 2.5-11 on SELinux. This affects an unknown part of the component Filesystem. Executing a manipulation can lead to link following. This vulnerability appears as CVE-2018-1063. The attack requires local access. There is no available exploit. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in policycoreutils 2.5-11 on SELinux. It has been declared as problematic. This vulnerability affects an unknown code block of the component Filesystem. The manipulation with an unknown input leads to a link following vulnerability. The CWE definition for the vulnerability is CWE-59. The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

Context relabeling of filesystems is vulnerable to symbolic link attack, allowing a local, unprivileged malicious entity to change the SELinux context of an arbitrary file to a context with few restrictions. This only happens when the relabeling process is done, usually when taking SELinux state from disabled to enable (permissive or enforcing). The issue was found in policycoreutils 2.5-11.

The bug was discovered 02/28/2018. The weakness was presented 03/02/2018 as Bug 1550122 as not defined bug report (Bugzilla). The advisory is shared for download at bugzilla.redhat.com. This vulnerability was named CVE-2018-1063 since 12/04/2017. The attack needs to be approached locally. No form of authentication is required for a successful exploitation. There are neither technical details nor an exploit publicly available.

The vulnerability was handled as a non-public zero-day exploit for at least 2 days. During that time the estimated underground price was around $0-$5k. The vulnerability scanner Nessus provides a plugin with the ID 108991 (RHEL 7 : policycoreutils (RHSA-2018:0913)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Red Hat Local Security Checks and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 351374 (Amazon Linux Security Advisory for policycoreutils: ALAS2-2018-1076).

Upgrading eliminates this vulnerability. A possible mitigation has been published 2 months after the disclosure of the vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (108991). Once again VulDB remains the best source for vulnerability data.

Productinfo

Name

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 4.9
VulDB Meta Temp Score: 4.8

VulDB Base Score: 5.3
VulDB Temp Score: 5.1
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 4.4
NVD Vector: 🔍

CVSSv2info

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

NVD Base Score: 🔍

Exploitinginfo

Class: Link following
CWE: CWE-59
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: 108991
Nessus Name: RHEL 7 : policycoreutils (RHSA-2018:0913)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

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

Timelineinfo

12/04/2017 🔍
02/28/2018 +86 days 🔍
03/02/2018 +2 days 🔍
03/02/2018 +0 days 🔍
03/03/2018 +1 days 🔍
04/10/2018 +38 days 🔍
04/11/2018 +1 days 🔍
01/10/2020 +639 days 🔍

Sourcesinfo

Advisory: Bug 1550122
Status: Not defined
Confirmation: 🔍

CVE: CVE-2018-1063 (🔍)
GCVE (CVE): GCVE-0-2018-1063
GCVE (VulDB): GCVE-100-114028

Entryinfo

Created: 03/03/2018 10:07
Updated: 01/10/2020 08:59
Changes: 03/03/2018 10:07 (69), 01/10/2020 08:59 (5)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

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