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Use-after-free when response filters increase response data, and increased data exceeds downstream buffer limits.

Moderate
mattklein123 published GHSA-h69p-g6xg-mhhh Feb 22, 2022

Package

No package listed

Affected versions

v1.21.0 and earlier

Patched versions

1.18.6, 1.19.3, 1.20.2, 1.21.1

Description

CVSS Score 6.1 AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:L, Medium

Sending a locally generated response must stop further processing of request or response data. Envoy tracks the amount of buffered request and response data and aborts the request if the amount of buffered data is over the limit by sending 413 or 500 responses. However when the buffer overflows while response is processed by the filter chain the operation may not be aborted correctly and result in accessing a freed memory block.

Impact

Denial of Service

Patches

Has the problem been patched? What versions should users upgrade to?

Workarounds

Disable filters that may modify a response body and increase its size if feasible.

References

https://blog.envoyproxy.io
https://github.com/envoyproxy/envoy/releases

For more information

Open an issue in Envoy repo
Email us at envoy-security

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
Required
Scope
Changed
Confidentiality
None
Integrity
Low
Availability
Low

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:L

CVE ID

CVE-2021-43825

Weaknesses