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Full authentication bypass if SASL authorization username is specified

Critical severity GitHub Reviewed Published Mar 13, 2023 in foxcpp/maddy • Updated Mar 14, 2023

Package

gomod github.com/foxcpp/maddy (Go)

Affected versions

>= 0.2.0, < 0.6.3

Patched versions

0.6.3

Description

Impact

maddy 0.2.0 - 0.6.2 allows a full authentication bypass if SASL authorization username is specified when using the PLAIN authentication mechanisms. Instead of validating the specified authorization username, it is accepted as is after checking the credentials for the authentication username.

Patches

maddy 0.6.3 includes the fix for the bug.

Workarounds

There is no way to fix the issue without upgrading.

References

References

@foxcpp foxcpp published to foxcpp/maddy Mar 13, 2023
Published by the National Vulnerability Database Mar 13, 2023
Published to the GitHub Advisory Database Mar 14, 2023
Reviewed Mar 14, 2023
Last updated Mar 14, 2023

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
High
Availability
None

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:N/S:U/C:H/I:H/A:N

EPSS score

0.245%
(64th percentile)

Weaknesses

CVE ID

CVE-2023-27582

GHSA ID

GHSA-4g76-w3xw-2x6w

Source code

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