Inconsistent interpretation of HTTP requests in Varnish Cache and Varnish Enterprise - CVE-2025-47905
Published: May 13, 2025 / Updated: May 21, 2025
Vulnerability identifier: #VU109043
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2025-47905
CWE-ID: CWE-444
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Varnish Software
Affected software:
Varnish Cache
Varnish Enterprise
Varnish Cache
Varnish Enterprise
Detailed vulnerability description
The vulnerability allows a remote attacker to perform HTTP request smuggling attacks.
The vulnerability exists due to improper validation of HTTP/1 requests. A remote attacker can send a specially crafted HTTP request to the server and smuggle arbitrary HTTP headers.
Successful exploitation of vulnerability may allow an attacker to poison HTTP cache and perform phishing attacks.
How to mitigate CVE-2025-47905
Install updates from vendor's website.