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5.5
MEDIUM CVSS 3.1
CVE-2021-27851
Guix Daemon Local Privilege Escalation Hardlink Manipulation
Description

A security vulnerability that can lead to local privilege escalation has been found in ’guix-daemon’. It affects multi-user setups in which ’guix-daemon’ runs locally. The attack consists in having an unprivileged user spawn a build process, for instance with `guix build`, that makes its build directory world-writable. The user then creates a hardlink to a root-owned file such as /etc/shadow in that build directory. If the user passed the --keep-failed option and the build eventually fails, the daemon changes ownership of the whole build tree, including the hardlink, to the user. At that point, the user has write access to the target file. Versions after and including v0.11.0-3298-g2608e40988, and versions prior to v1.2.0-75109-g94f0312546 are vulnerable.

INFO

Published Date :

April 26, 2021, 4:15 p.m.

Last Modified :

Nov. 21, 2024, 5:58 a.m.

Remotely Exploit :

No

Source :

[email protected]
Affected Products

The following products are affected by CVE-2021-27851 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Gnu guix
: Total Affected Vendor : 1 | Products : 1
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 2.0 LOW [email protected]
CVSS 3.1 MEDIUM [email protected]
Solution
Update Guix to patch a local privilege escalation vulnerability.
  • Update Guix to the latest version.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2021-27851.

URL Resource
https://bugs.gnu.org/47229 Issue Tracking Mailing List Patch Vendor Advisory
https://guix.gnu.org/en/blog/2021/risk-of-local-privilege-escalation-via-guix-daemon/ Patch Vendor Advisory
https://bugs.gnu.org/47229 Issue Tracking Mailing List Patch Vendor Advisory
https://guix.gnu.org/en/blog/2021/risk-of-local-privilege-escalation-via-guix-daemon/ Patch Vendor Advisory
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2021-27851 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2021-27851 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2021-27851 vulnerability anywhere in the article.

Results are limited to the first 20 news articles due to potential performance issues.

The following table lists the changes that have been made to the CVE-2021-27851 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by af854a3a-2127-422b-91ae-364da2661108

    Nov. 21, 2024

    Action Type Old Value New Value
    Added Reference https://bugs.gnu.org/47229
    Added Reference https://guix.gnu.org/en/blog/2021/risk-of-local-privilege-escalation-via-guix-daemon/
  • CVE Modified by [email protected]

    May. 14, 2024

    Action Type Old Value New Value
  • Reanalysis by [email protected]

    Jul. 29, 2022

    Action Type Old Value New Value
    Removed CWE NIST CWE-269
    Added CWE NIST CWE-59
  • Initial Analysis by [email protected]

    May. 07, 2021

    Action Type Old Value New Value
    Added CVSS V2 NIST (AV:L/AC:L/Au:N/C:N/I:P/A:N)
    Added CVSS V3.1 NIST AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
    Changed Reference Type https://bugs.gnu.org/47229 No Types Assigned https://bugs.gnu.org/47229 Issue Tracking, Mailing List, Patch, Vendor Advisory
    Changed Reference Type https://guix.gnu.org/en/blog/2021/risk-of-local-privilege-escalation-via-guix-daemon/ No Types Assigned https://guix.gnu.org/en/blog/2021/risk-of-local-privilege-escalation-via-guix-daemon/ Patch, Vendor Advisory
    Added CWE NIST CWE-269
    Added CPE Configuration OR *cpe:2.3:a:gnu:guix:*:*:*:*:*:*:*:* versions from (including) 0.11.0 up to (excluding) 1.2.0
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
Vulnerability Scoring Details
Base CVSS Score: 5.5
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality Impact
Integrity Impact
Availability Impact
Base CVSS Score: 2.1
Access Vector
Access Complexity
Authentication
Confidentiality Impact
Integrity Impact
Availability Impact
Exploit Prediction

EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days.

0.04 }} -0.03%

score

0.09170

percentile