CVE intelligence and bounded remediation
CVE-2023-27582 — maddy is a composable, all-in-one mail server
maddy is a composable, all-in-one mail server. Starting with version 0.2.0 and prior to version 0.6.3, maddy allows a full authentication bypass if SASL authorization username is specified when using the PLAIN authentication mechanisms. Instead of validating the specified username, it is accepted as is after checking the credentials for the authentication username. maddy 0.6.3 includes the fix for the bug. There are no known workarounds.
- Severity
- Critical
- CVSS
- 9.8 (3.1)
- Published
- 2023-03-13
- CISA KEV
- Not currently listed
- Ecosystem
- software/application
- Weaknesses
- CWE-287, CWE-305
Affected products
- maddy_project / maddy
Matched remediation archetype
Authentication bypass and missing authentication
This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.
Check exposure
- Map every affected endpoint and protocol path, including alternate ports, legacy routes, recovery flows, service accounts, and machine-to-machine access.
- Confirm which deployments enable the affected authentication mode and whether the interface is reachable from untrusted networks.
- Review session, token, credential, and proxy trust configuration without attempting account takeover.
Remediate safely
- Apply the supported fix and centralize fail-closed authentication before protected request handling.
- Remove default or embedded credentials, rotate affected secrets and sessions, and bind authentication decisions to the intended audience and channel.
- Add negative tests for alternate routes, malformed or absent credentials, recovery flows, and proxy-derived identity.
Authoritative sources
Complete CVE record and remediation plan
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