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OpenStack os-vif Ageing time of 0 disables linuxbridge MAC learning

Critical severity GitHub Reviewed Published May 24, 2022 to the GitHub Advisory Database • Updated May 2, 2024

Package

pip os-vif (pip)

Affected versions

>= 1.15.0, < 1.15.2
= 1.16.0

Patched versions

1.15.2
1.17.0

Description

In OpenStack os-vif 1.15.x before 1.15.2, and 1.16.0, a hard-coded MAC aging time of 0 disables MAC learning in linuxbridge, forcing obligatory Ethernet flooding of non-local destinations, which both impedes network performance and allows users to possibly view the content of packets for instances belonging to other tenants sharing the same network. Only deployments using the linuxbridge backend are affected. This occurs in PyRoute2.add() in internal/command/ip/linux/impl_pyroute2.py.

References

Published by the National Vulnerability Database Aug 28, 2019
Published to the GitHub Advisory Database May 24, 2022
Reviewed May 2, 2024
Last updated May 2, 2024

Severity

Critical

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
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
High

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

EPSS score

0.433%
(75th percentile)

Weaknesses

CVE ID

CVE-2019-15753

GHSA ID

GHSA-mcpw-cp35-p3h8

Source code

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