CVE-2021-24905

Advanced Contact form 7 DB <= 1.8.6 - Authenticated Arbitrary File Deletion

2022-02-22 00:00
Krzysztof Zając

Strategic Overview

Status
Patched in 1.8.7
Affected Plugin
Advanced Contact form 7 DB
Affected Version
< 1.8.7
CVSS
8.8High
Weakness type
CWE-863 · Incorrect Authorization
CVE
CVE-2021-24905
View all Advanced Contact form 7 DB vulnerabilities

At a glance

CVE-2021-24905 is a high-severity Incorrect Authorization vulnerability in the Advanced Contact form 7 DB WordPress plugin, affecting versions < 1.8.7. It carries a CVSS score of 8.8 (reachable over the network; low attack complexity; high confidentiality, integrity, availability impact). Exploitation requires an authenticated account. The issue is fixed in version 1.8.7; sites on affected versions should update now. Disclosed February 2022, reported by Krzysztof Zając.

Vulnerability Overview

The Advanced Contact form 7 DB WordPress plugin before 1.8.7 does not have authorisation nor CSRF checks in the acf7_db_edit_scr_file_delete AJAX action, and does not validate the file to be deleted, allowing any authenticated user to delete arbitrary files on the web server. For example, removing the wp-config.php allows attackers to trigger WordPress setup again, gain administrator privileges and execute arbitrary code or display arbitrary content to the users.

Technical Analysis

The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no interaction from a victim user. A successful exploit has high impact on confidentiality, integrity, availability — full site compromise territory.

CWE-863: Incorrect Authorization

Reaching this weakness in Advanced Contact form 7 DB < 1.8.7 takes any authenticated account. Incorrect authorization means a permission check exists but evaluates the wrong thing, so it passes for callers it was meant to stop.

The action runs for users the code intended to exclude, with the same effect as having no check at all. For Advanced Contact form 7 DB the fix is 1.8.7: builds < 1.8.7 are affected, anything from 1.8.7 onward is not.

Remediation

Update to version 1.8.7, or a newer patched version

How does WordSec protect against this?

Because it turns on account access, WordSec's login security is the relevant layer: role-based two-factor, captcha and brute-force limits raise the cost of getting the account this needs. None of that substitutes for the fix: Advanced Contact form 7 DB 1.8.7 closes this, and updating the plugin is the step that ends it.

  • Login Security
  • Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2021-24905https://www.wordfence.com/threat-intel/vulnerabilities/id/4891fd3f-563b-497a-a5d9-617f4862298bhttps://nvd.nist.gov/vuln/detail/CVE-2021-24905

Related records

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