CVE-2021-36766
Concrete5 through 8.5.5 deserializes Untrusted Data. The vulnerable code is located within the…
- 7.2HighCVSS base score
- 3.7%Exploitation in 30 daysEPSS · top 10% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
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.
Timeline
ID reserved
By mitre
- 11 days later
· 11 days later
Published
- 3 years later
· 3 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| NVDNVD · Modified | 3.1 | High7.2 | CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 3.7% · top 10% of all CVEs (12 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.2.
Affected products
n/a
- affected n/a
References
References3
- https://hackerone.com/reports/1063039 (opens in a new tab)x_refsource_MISCx_transferred
- 20210719 [KIS-2021-05] Concrete5 <= 8.5.5 (Logging Settings) Phar Deserialization Vulnerability (opens in a new tab)mailing-listx_refsource_FULLDISCx_transferred
- http://packetstormsecurity.com/files/163564/Concrete5-8.5.5-Phar-Deserialization.html (opens in a new tab)x_refsource_MISCx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2021-23354 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2021-36766)Record last updated .