CVE-2025-4600

HTTP Request Smuggling in Google Cloud Classic Application Load Balancer due to Improper Chunked Encoding Validation

State: Published
Severity: 8.7 High
Published: May 16, 2025
Updated: Sep 8, 2025
Reserved: May 12, 2025

Description

A request smuggling vulnerability existed in the Google Cloud Classic Application Load Balancer due to improper handling of chunked-encoded HTTP requests. This allowed attackers to craft requests that could be misinterpreted by backend servers. The issue was fixed by disallowing stray data after a chunk, and is no longer exploitable. No action is required as Classic Application Load Balancer service after 2025-04-26 is not vulnerable.

Scores

CVSS	Score	Vector	Source
4.0	8.7 High	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:L/SI:L/SA:L	Google

Weaknesses

CWE-444 Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')

Affected Products

Product	Versions
Classic Application Load BalancerGoogle Cloud	0Affected

References

https://cloud.google.com/support/bulletins#gcp-2025-027

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