CVE-2024-39305: Envoy is a cloud-native, open source edge and service proxy. Prior to versions 1.30.4, 1.29.7, 1.28.5, and 1.27.7. Envoy references already freed memo...

Description

Envoy is a cloud-native, open source edge and service proxy. Prior to versions 1.30.4, 1.29.7, 1.28.5, and 1.27.7. Envoy references already freed memory when route hash policy is configured with cookie attributes. Note that this vulnerability has been fixed in the open as the effect would be immediately apparent if it was configured. Memory allocated for holding attribute values is freed after configuration was parsed. During request processing Envoy will attempt to copy content of de-allocated memory into request cookie header. This can lead to arbitrary content of Envoy's memory to be sent to the upstream service or abnormal process termination. This vulnerability is fixed in Envoy versions v1.30.4, v1.29.7, v1.28.5, and v1.27.7. As a workaround, do not use cookie attributes in route action hash policy.

Metrics

CVSS 3.1

9.1/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

EPSS Probability

0.65%

46.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-416

Affected Software

Vendor	Product	Versions
Envoyproxy	Envoy	1.27.6
Envoyproxy	Envoy	1.28.4
Envoyproxy	Envoy	1.29.6
Envoyproxy	Envoy	1.30.3

References

Timeline

Published: Jul 1, 2024
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2024-39305?

Envoy is a cloud-native, open source edge and service proxy. Prior to versions 1.30.4, 1.29.7, 1.28.5, and 1.27.7. Envoy references already freed memory when route hash policy is configured with cookie attributes. Note that this vulnerability has been fixed in the open as the effect would be immediately apparent if it was configured. Memory allocated for holding attribute values is freed after configuration was parsed. During request processing Envoy will attempt to copy content of de-allocated memory into request cookie header. This can lead to arbitrary content of Envoy's memory to be sent to the upstream service or abnormal process termination. This vulnerability is fixed in Envoy versions v1.30.4, v1.29.7, v1.28.5, and v1.27.7. As a workaround, do not use cookie attributes in route action hash policy.

How severe is CVE-2024-39305?

CVE-2024-39305 has a CVSS score of 9.1/10 (CRITICAL severity). The EPSS model estimates a 0.65% probability of exploitation in the next 30 days.

How do I fix CVE-2024-39305?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.