CVE-2021-36766

7.2 HIGH 4% exploit odds No fix listed

What it is

Concrete5 through 8.5.5 deserializes Untrusted Data. The vulnerable code is located within the controllers/single_page/dashboard/system/environment/logging.php Logging::update_logging() method. User input passed through the logFile request parameter is not properly sanitized before being used in a call to the file_exists() PHP function. This can be exploited by malicious users to inject arbitrary PHP objects into the application scope (PHP Object Injection via phar:// stream wrapper), allowing them to carry out a variety of attacks, such as executing arbitrary PHP code.

At a glance

Exploitability: Can be exploited over the network with an admin-level account. High risk of data exposure, data tampering, service disruption.
Exploit odds: 3.7% chance of exploitation in the next 30 days (EPSS).
Fix: No patch or advisory is linked yet. Look at mitigations or restrict exposure.

Timeline

2021-07-30 14:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2026-06-17 03:59 UTC Last updatedMost recent change to the record

Why it ranks here

Exploited in the wild: no, CISA does not list it.
Exploit odds: 3.7% in the next 30 days (EPSS).
Severity: 7.2 HIGH (CVSS).
Fix: none linked yet, which raises it.

Details

Published: 2021-07-30 14:15 UTC
Last modified: 2026-06-17 03:59 UTC
Exploit probability: 3.7% · EPSS, next 30 days
Weakness: CWE-502 · Unsafe deserialization
Record status: Modified

Affected

Concretecms Concrete Cms < 8.5.6

Attack profile CVSS 3.1 · 7.2

Attack vector: Network
Complexity: Low
Privileges needed: High
User interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: High

Raw vector

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

Is it in your code?

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References

NVD record · CVE.org record