Authentication Bypass Vulnerability in Eclipse Mosquitto 1.0 to 1.5.5

CVE-2018-12551 · MEDIUM Severity

AV:N/AC:M/AU:N/C:P/I:P/A:P

When Eclipse Mosquitto version 1.0 to 1.5.5 (inclusive) is configured to use a password file for authentication, any malformed data in the password file will be treated as valid. This typically means that the malformed data becomes a username and no password. If this occurs, clients can circumvent authentication and get access to the broker by using the malformed username. In particular, a blank line will be treated as a valid empty username. Other security measures are unaffected. Users who have only used the mosquitto_passwd utility to create and modify their password files are unaffected by this vulnerability.

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