VulnerabilityPublished 22 Jan 2024Updated 30 May 2025

CVE-2020-36772: Cloudlinux OS cagefs · External Control of File Name or Path

Affects Cloudlinux OS cagefsSource CVE Database V5

Not known to be exploited · CVSS 4.4 Medium.

Data as of 26 Oct 2026, 14:05 UTC

CVSS 3.1 base score

4.4Medium

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

EPSS: 0.3% chance of exploitation in 30 days – higher than 31% 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:L/I:L/A:N

Attack Vector: Local
Attack Complexity: Low
Privileges Required: Low
User Interaction: None
Scope: Unchanged
Confidentiality: Low
Integrity: Low
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: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on 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 22 Jan 2024
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 26 Oct 2026.

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 or the CVSS exploit maturity 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
Cloudlinuxcloudlinux/cagefs`pkg:rpm/cloudlinux/cagefs`Other threats	Affected <=7.0.8-2	Fixed in–

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

AI-suggested

European organizations should prioritize upgrading CageFS to a version later than 7.0.8-2 where this vulnerability is addressed. In the absence of an official patch, administrators should implement strict access controls to limit local user privileges and monitor for unusual file access patterns indicative of exploitation attempts. Employing file integrity monitoring on critical system and application files can help detect unauthorized modifications. Additionally, isolating user environments further by using containerization or virtualization technologies beyond CageFS can reduce the attack surface. Regular audits of user permissions and restricting the use of sendmail proxy commands to trusted users can also mitigate risk. Organizations should ensure that logging is enabled and monitored for suspicious activities related to file access outside of CageFS. Finally, educating system administrators and users about the risks of local privilege escalation and maintaining up-to-date security policies will help reduce the likelihood and impact of exploitation.

Description

CloudLinux CageFS 7.0.8-2 or below insufficiently restricts file paths supplied to the sendmail proxy command. This allows local users to read and write arbitrary files of certain file formats outside the CageFS environment.

Impact

For European organizations, especially those relying on shared hosting environments or using CloudLinux OS with CageFS for multi-tenant isolation, this vulnerability poses a risk of local privilege escalation and unauthorized file access. The ability for a local user to read and write arbitrary files outside their CageFS jail could lead to exposure of sensitive data, including configuration files, credentials, or proprietary information. This undermines the confidentiality and integrity of hosted applications and data. While the vulnerability does not directly impact availability, the unauthorized file modifications could disrupt service integrity or lead to further exploitation. Organizations in sectors with strict data protection regulations, such as finance, healthcare, and government, could face compliance risks if sensitive data is exposed. Additionally, shared hosting providers in Europe could see reputational damage and customer trust erosion if this vulnerability is exploited. The requirement for local access limits remote exploitation but does not eliminate risk, as attackers who gain initial footholds through other means could leverage this vulnerability for lateral movement or privilege escalation within the hosting environment.

CWE-73External Control of File Name or Path (opens in a new tab)
Base weaknessLikelihood of exploit: HighOWASP Top 10 A06:2025: Insecure Design (opens in a new tab)
The product allows user input to control or influence paths or file names that are used in filesystem operations.
Architecture and Design
When the set of filenames is limited or known, create a mapping from a set of fixed input values (such as numeric IDs) to the actual filenames, and reject all other inputs. For example, ID 1 could map to "inbox.txt" and ID 2 could map to "profile.txt".
Architecture and Design · Operation
Run your code in a "jail" or similar sandbox environment that enforces strict boundaries between the process and the operating system. This may effectively restrict all access to files within a particular directory.
Architecture and Design
For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks…
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
Secure Design Principles (opens in a new tab)
OWASP ASVS 4.0.3
V12.3.2 (opens in a new tab)
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
Attack patterns
Subverting Environment Variable Values (opens in a new tab)
Leverage Alternate Encoding (opens in a new tab)
Using Slashes and URL Encoding Combined to Bypass Validation Logic (opens in a new tab)
URL Encoding (opens in a new tab)
Manipulating Web Input to File System Calls (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

Loading reviews…

Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 8 Jul 2025, 16:25 UTC

WeaknessesCWE-73

Technical details

References

Community reviews

Related threats