CVE-2023-27496 - CVE House
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Status published Medium CVE-2023-27496

Envoy may crash when a redirect url without a state param is received in the oauth filter

Vulnerability Description

Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to versions 1.26.0, 1.25.3, 1.24.4, 1.23.6, and 1.22.9, the OAuth filter assumes that a `state` query param is present on any response that looks like an OAuth redirect response. Sending it a request with the URI path equivalent to the redirect path, without the `state` parameter, will lead to abnormal termination of Envoy process. Versions 1.26.0, 1.25.3, 1.24.4, 1.23.6, and 1.22.9 contain a patch. The issue can also be mitigated by locking down OAuth traffic, disabling the filter, or by filtering traffic before it reaches the OAuth filter (e.g. via a lua script).

Impact Analysis

Refer to official advisory for detailed impact metrics.

Remediation

Ensure systems are updated to the latest vendor-supplied patch levels.

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Credits & Attribution

No credits recorded in the NVD database.

References

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Affected Vendor

Affected Software

envoy
Vulnerable Versions:
>= 1.25.0, < 1.25.3, >= 1.24.0, < 1.24.4, >= 1.23.0, < 1.23.6, < 1.22.9

Timeline

Official Publish: April 4th, 2023
Last Modified: February 10th, 2025
Added to House: July 22nd, 2026

CVSS Vectors

V3: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

Weaknesses (CWE)

CWE-20

MITRE ATT&CK TTPs

T1190 Exploit Public-Facing Application
Initial Access
T1059 Command and Scripting Interpreter
Execution
T1068 Exploitation for Privilege Escalation
Privilege Escalation
T1213 Data from Information Repositories
Collection
T1565.002 Stored Data Manipulation
Impact