CVE-2021-20714

WP Fastest Cache <= 0.9.1.6 - Authenticated (Admin+) Directory Traversal to Arbitrary File Deletion

2021-04-27 00:00
Gen Sato

Strategic Overview

Status
Patched in 0.9.1.7
Affected Plugin
WP Fastest Cache – WordPress Cache Plugin
Affected Version
< 0.9.1.7
CVSS
6.5Medium
Weakness type
CWE-22 · Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
CVE
CVE-2021-20714
View all WP Fastest Cache – WordPress Cache Plugin vulnerabilities

At a glance

CVE-2021-20714 is a medium-severity Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') vulnerability in the WP Fastest Cache WordPress plugin, affecting versions < 0.9.1.7. It carries a CVSS score of 6.5 (reachable over the network; low attack complexity; high integrity, availability impact). Exploitation requires an authenticated account at Admin level or above. The issue is fixed in version 0.9.1.7; sites on affected versions should update now. Disclosed April 2021, reported by Gen Sato.

Vulnerability Overview

Directory traversal vulnerability in WP Fastest Cache versions prior to 0.9.1.7 allows a remote attacker with administrator privileges to delete arbitrary files on the server via unspecified vectors.

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 integrity, availability.

CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

Reaching this weakness in WP Fastest Cache < 0.9.1.7 takes an account at Admin level or above. Path traversal happens when user-controlled text is used to build a filesystem path without being constrained to an intended directory, so sequences like ../ walk the resolved path somewhere else.

Depending on the operation, it means reading files outside the intended folder — wp-config.php being the usual target — or writing to and deleting paths the web server can touch. For WP Fastest Cache the fix is 0.9.1.7: builds < 0.9.1.7 are affected, anything from 0.9.1.7 onward is not.

Remediation

Update to version 0.9.1.7, or a newer patched version

How does WordSec protect against this?

An attacker needs Admin access first, so the firewall sees the attempt as traffic from a logged-in account: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: WP Fastest Cache 0.9.1.7 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2021-20714https://www.wordfence.com/threat-intel/vulnerabilities/id/20989781-def0-4ffd-bf24-40ed34b3e922https://nvd.nist.gov/vuln/detail/CVE-2021-20714

Related records

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