CVE-2025-55162
MEDIUMCVSS Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:L/A:N
Lifecycle Timeline
4Description
Envoy is an open source L7 proxy and communication bus designed for large modern service oriented architectures. In versions below 1.32.10 and 1.33.0 through 1.33.6, 1.34.0 through 1.34.4 and 1.35.0, insufficient Session Expiration in the Envoy OAuth2 filter leads to failed logout operations. When configured with __Secure- or __Host- prefixed cookie names, the filter fails to append the required Secure attribute to the Set-Cookie header during deletion. Modern browsers ignore this invalid request, causing the session cookie to persist. This allows a user to remain logged in after they believe they have logged out, creating a session hijacking risk on shared computers. The current implementation iterates through the configured cookie names to generate deletion headers but does not check for these prefixes. This failure to properly construct the deletion header means the user's session cookies are never removed by the browser, leaving the session active and allowing the next user of the same browser to gain unauthorized access to the original user's account and data. This is fixed in versions 1.32.10, 1.33.7, 1.34.5 and 1.35.1.
Analysis
Envoy is an open source L7 proxy and communication bus designed for large modern service oriented architectures. Rated medium severity (CVSS 6.3), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
Technical Context
This vulnerability is classified under CWE-613. Envoy is an open source L7 proxy and communication bus designed for large modern service oriented architectures. In versions below 1.32.10 and 1.33.0 through 1.33.6, 1.34.0 through 1.34.4 and 1.35.0, insufficient Session Expiration in the Envoy OAuth2 filter leads to failed logout operations. When configured with __Secure- or __Host- prefixed cookie names, the filter fails to append the required Secure attribute to the Set-Cookie header during deletion. Modern browsers ignore this invalid request, causing the session cookie to persist. This allows a user to remain logged in after they believe they have logged out, creating a session hijacking risk on shared computers. The current implementation iterates through the configured cookie names to generate deletion headers but does not check for these prefixes. This failure to properly construct the deletion header means the user's session cookies are never removed by the browser, leaving the session active and allowing the next user of the same browser to gain unauthorized access to the original user's account and data. This is fixed in versions 1.32.10, 1.33.7, 1.34.5 and 1.35.1. Affected products include: Envoyproxy Envoy. Version information: through 1.33.6.
Affected Products
Envoyproxy Envoy.
Remediation
No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Apply vendor patches when available. Implement network segmentation and monitoring as interim mitigations.
Priority Score
Vendor Status
Share
External POC / Exploit Code
Leaving vuln.today