Inconsistent interpretation of HTTP requests in Varnish Enterprise and Varnish Cache - CVE-2025-30346
Published: March 18, 2025 / Updated: March 25, 2025
Vulnerability identifier: #VU105850
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-2025-30346
CWE-ID: CWE-444
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Varnish Software
Affected software:
Varnish Enterprise
Varnish Cache
Varnish Enterprise
Varnish Cache
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 client-side desync 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-2025-30346
Install updates from vendor's website.