CVE-2017-18018VulnerabilityPublished 4 Jan 2018Updated 9 Jun 2025

CVE-2017-18018: n/a

Source CVE Database V5

Not known to be exploited · CVSS 7.1 High.

Data as of 26 Oct 2026, 07:57 UTC

CVSS 3.1 base score

7.1High

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.3% chance of exploitation in 30 days – higher than 27% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

Attack Vector: Local
Attack Complexity: Low
Privileges Required: Low
User Interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Local: The vulnerable component is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Either: the attacker exploits the vulnerability by accessing the target system locally (e.g., keyboard, console), or remotely (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., tricking a legitimate user into opening a malicious document).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 4 Jan 2018
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-26.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
Debiandebian/coreutils`pkg:deb/debian/coreutils`Other threats	Affected >=8.0.0 <=8.29	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

To mitigate CVE-2017-18018, European organizations should: 1) Upgrade GNU Coreutils to a version later than 8.29 where the vulnerability is fixed. If an upgrade is not immediately possible, consider applying vendor-supplied patches or backported fixes. 2) Audit and review scripts and automation tools that use chown or chgrp with recursive "-R -L" options to avoid following symbolic links during ownership changes. Prefer using "-R -P" (do not follow symlinks) or explicitly avoid the "-L" option unless necessary. 3) Restrict local user permissions to minimize the ability of unprivileged users to execute ownership changes or replace files with symbolic links in sensitive directories. 4) Implement file system monitoring to detect unexpected changes in file ownership or the presence of suspicious symbolic links in critical paths. 5) Employ mandatory access controls (e.g., SELinux, AppArmor) to limit the impact of unauthorized ownership changes. 6) Educate system administrators about the risks of recursive ownership changes involving symbolic links and encourage best practices to avoid race conditions. These targeted actions go beyond generic advice by focusing on the specific conditions that enable exploitation of this vulnerability.

Description

In GNU Coreutils through 8.29, chown-core.c in chown and chgrp does not prevent replacement of a plain file with a symlink during use of the POSIX "-R -L" options, which allows local users to modify the ownership of arbitrary files by leveraging a race condition.

Impact

For European organizations, the impact of CVE-2017-18018 can be significant, especially in environments where GNU Coreutils 8.29 or earlier versions are deployed. Since chown and chgrp are core utilities used in system administration, automation scripts, and software deployment, exploitation of this vulnerability could allow a local attacker to escalate privileges by changing ownership of critical system files or sensitive data. This could lead to unauthorized access, data breaches, or disruption of system integrity. The vulnerability does not directly affect availability, but the compromise of ownership could facilitate further attacks, including privilege escalation and persistence mechanisms. Organizations with multi-user systems, shared hosting environments, or those that allow untrusted users local access are at higher risk. Additionally, automated processes or scripts that use recursive ownership changes with symbolic link following could inadvertently enable exploitation. The lack of known exploits in the wild reduces immediate risk, but the fundamental nature of the vulnerability and the widespread use of GNU Coreutils mean that European organizations should prioritize mitigation to prevent potential exploitation.

CWE-362Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') (opens in a new tab)
Class weaknessLikelihood of exploit: MediumOWASP Top 10 A06:2025: Insecure Design (opens in a new tab)
The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.
Architecture and Design
In languages that support it, use synchronization primitives. Only wrap these around critical code to minimize the impact on performance.
Architecture and Design
Use thread-safe capabilities such as the data access abstraction in Spring.
Architecture and Design
Minimize the usage of shared resources in order to remove as much complexity as possible from the control flow and to reduce the likelihood of unexpected conditions occurring.
OWASP Cheat Sheets
Abuse Case (opens in a new tab)
Secure Design Principles (opens in a new tab)
OWASP ASVS 4.0.3
V1.11.2 (opens in a new tab)
Attack patterns
Leveraging Time-of-Check and Time-of-Use (TOCTOU) Race Conditions (opens in a new tab)
Leveraging Race Conditions (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

lists.gnu.org/archive/html/coreutils/2017-12/msg00045.html (opens in a new tab)

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 10 Jul 2025, 21:18 UTC

WeaknessesCWE-362

Technical details

References

Community reviews

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