Details for this vulnerability have not been published by NIST at this point. Descriptions from software vendor advisories for this issue are provided below.
From ALAS-2021-1486:
A flaw was found in cloud-init, where it uses the random.choice function when creating sensitive random strings used for generating a random password in new instances. Depending on the instance configuration, a remote or local attacker may abuse this vulnerability to guess the password of the victim user. (CVE-2020-8631)
A flaw was found in cloud-init, where it uses short passwords when generating a random password in new instances. Depending on the instance configuration, a remote or local attacker may abuse this vulnerability to guess the password of the victim user. (CVE-2020-8632)
A vulnerability was discovered in cloud-init which can improperly disclose randomly generated passwords as part of the chpasswd module. The fix prevents the generated password from being written to a world-readable log file on the local disk. (CVE-2021-3429)
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