CVE-2021-23394
Remote Code Execution (RCE)
The package studio-42/elfinder before 2.1.58 are vulnerable to Remote Code Execution (RCE) via execution of PHP code in a .phar file. NOTE: This only applies if the server parses .phar files as PHP.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
Remote Code Execution (RCE)
The package studio-42/elfinder before 2.1.58 are vulnerable to Remote Code Execution (RCE) via execution of PHP code in a .phar file. NOTE: This only applies if the server parses .phar files as PHP.
- Record
CVE-2021-23394- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
EUVDEUVD-2021-1383
The package studio-42/elfinder before 2.1.58 are vulnerable to Remote Code Execution (RCE) via execution of PHP code in a .phar file. NOTE: This only applies if the server parses .phar files as PHP.
- Record
EUVD-2021-1383- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-qm58-cvvm-c5qr
elFinder unsafe upload filtering leading to remote code execution
Impact
Before elFinder 2.1.58, the upload filter did not disallow the upload of .phar files. As several Linux distributions are now shipping Apache configured in a way it will process these files as PHP scripts, attackers could gain arbitrary code execution on the server hosting the PHP connector (even in minimal configuration).
Patches
The issue has been addressed with https://github.com/Studio-42/elFinder/commit/75ea92decc16a5daf7f618f85dc621d1b534b5e1, associating .phar files to the right MIME type. Unless explicitly allowed in the configuration, such files cannot be uploaded anymore. This patch is part of the last release of elFinder, 2.1.58.
Workarounds
If you can't update to 2.1.58, make sure your connector is not exposed without authentication.
Important tips
Server-side scripts can often be created as text files. Currently, elFinder has an appropriate MIME type set for file extensions that are generally runnable on a web server.
However, the server has various settings. In some cases, the executable file may be judged as "text/plain". Therefore, elFinder installers should understand the extensions that can be executed on the web server where elFinder is installed, and check if there are any missing items in the elFinder settings.
The elFinder PHP connector has an option "additionalMimeMap" that specifies the MIME type for each extension. See #3295(comment) for more information.
References
- https://snyk.io/vuln/composer:studio-42%2Felfinder
- https://github.com/Studio-42/elFinder/issues/3295
- Further technical details will be disclosed on https://blog.sonarsource.com/tag/security after some time.
For more information
If you have any questions or comments about this advisory, you can contact:
- The original reporters, by sending an email to support [at] snyk.io or vulnerability.research [at] sonarsource.com;
- The maintainers, by opening an issue on this repository.
- Record
GHSA-qm58-cvvm-c5qr- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-434
- Updated
- 2026-11-02
NVD
The package studio-42/elfinder before 2.1.58 are vulnerable to Remote Code Execution (RCE) via execution of PHP code in a .phar file. NOTE: This only applies if the server parses .phar files as PHP.
- Record
CVE-2021-23394- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - CVSS 2.0
- 6.8 Medium
AV:N/AC:M/Au:N/C:P/I:P/A:P - Weakness
- CWE-434
- Updated
- 2026-11-02
OSV
The package studio-42/elfinder before 2.1.58 are vulnerable to Remote Code Execution (RCE) via execution of PHP code in a .phar file. NOTE: This only applies if the server parses .phar files as PHP.
- Record
CVE-2021-23394- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSVGHSA-qm58-cvvm-c5qr
elFinder unsafe upload filtering leading to remote code execution
Impact
Before elFinder 2.1.58, the upload filter did not disallow the upload of .phar files. As several Linux distributions are now shipping Apache configured in a way it will process these files as PHP scripts, attackers could gain arbitrary code execution on the server hosting the PHP connector (even in minimal configuration).
Patches
The issue has been addressed with https://github.com/Studio-42/elFinder/commit/75ea92decc16a5daf7f618f85dc621d1b534b5e1, associating .phar files to the right MIME type. Unless explicitly allowed in the configuration, such files cannot be uploaded anymore. This patch is part of the last release of elFinder, 2.1.58.
Workarounds
If you can't update to 2.1.58, make sure your connector is not exposed without authentication.
Important tips
Server-side scripts can often be created as text files. Currently, elFinder has an appropriate MIME type set for file extensions that are generally runnable on a web server.
However, the server has various settings. In some cases, the executable file may be judged as "text/plain". Therefore, elFinder installers should understand the extensions that can be executed on the web server where elFinder is installed, and check if there are any missing items in the elFinder settings.
The elFinder PHP connector has an option "additionalMimeMap" that specifies the MIME type for each extension. See #3295(comment) for more information.
References
- https://snyk.io/vuln/composer:studio-42%2Felfinder
- https://github.com/Studio-42/elFinder/issues/3295
- Further technical details will be disclosed on https://blog.sonarsource.com/tag/security after some time.
For more information
If you have any questions or comments about this advisory, you can contact:
- The original reporters, by sending an email to support [at] snyk.io or vulnerability.research [at] sonarsource.com;
- The maintainers, by opening an issue on this repository.
- Record
GHSA-qm58-cvvm-c5qr- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-434
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
studio-42/elfinderPackagist |
before 2.1.58 | 2.1.58 |
studio-42/elfinderPackagist |
before 2.1.58, plus listed versions 2.0.32.0.42.0.52.0.62.0.7 Show 45 moreShow less2.0.82.0.92.1.02.1.12.1.102.1.112.1.122.1.132.1.142.1.152.1.162.1.172.1.182.1.192.1.22.1.202.1.212.1.222.1.232.1.242.1.252.1.262.1.272.1.282.1.292.1.32.1.302.1.312.1.322.1.332.1.342.1.352.1.362.1.372.1.382.1.392.1.42.1.402.1.412.1.422.1.432.1.442.1.452.1.462.1.47 |
2.1.58 |
Public exploits
Links only. Every CVE stores no exploit code.
| Source | Link | Date |
|---|---|---|
| Nuclei | elFinder < 2.1.58 - Remote Code Execution | |
| PoC in GitHub | 0xnemian/CVE-2021-23394 | 2025-11-30 |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases, published | EUVD | |
| first indexed | CVE List, GitHub Advisories, Nuclei, NVD, OSV, PoC in GitHub |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-23394 is a high vulnerability (CVSS 8.1) in Std42 Elfinder, published June 13, 2021. Public exploit code exists. EPSS puts the chance of exploitation in the next 30 days at 18.9%, the 97th percentile. Fixed in studio-42/elfinder 2.1.58.
References
snyk.io/vuln/SNYK-PHP-STUDIO42ELFINDER-1290554
github.com/Studio-42/elFinder
blog.sonarsource.com/elfinder-case-study-of-web-file-manager-vulnerabilities
nvd.nist.gov/vuln/detail/CVE-2021-23394
Left out here: 15 versions. The JSON record has them.