Server-Side Request Forgery (SSRF) in W3 Total Cache - #VU18406
Published: May 7, 2019
Vulnerability identifier: #VU18406
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N/E:P/U:Green
CVE-ID: N/A
CWE-ID: CWE-918
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Frederick Townes
Affected software:
W3 Total Cache
W3 Total Cache
Detailed vulnerability description
The disclosed vulnerability allows a remote attacker to perform SSRF attacks.
The vulnerability exists due to insufficient validation of user-supplied input in the opcache_flush_file() function that calls file_exists() function on attacker-controlled data. A remote attacker can send a specially crafted HTTP request to the "/wp-content/plugins/w3-total-cache/pub/opcache.php" URL and trick the application to initiate requests to arbitrary systems.
Successful exploitation of this vulnerability may allow a remote attacker gain access to sensitive data, located in the local network or send malicious requests to other servers from the vulnerable system.
Example:
curl 'http://[host]/wp-content/plugins/w3-total-cache/pub/opcache.php' --data 'nonce=974ca6ad15021a6668e7ae02e1be551c&command=flush_file&file=[TARGET_URL]'
Remediation
Install updates from vendor's website.