qmail-verify as used in netqmail 1.06 is prone to an information disclosure vulnerability. A local attacker can test for the existence of files and directories anywhere in the filesystem because qmail-verify runs as root and tests for the existence of files in the attacker's home directory, without dropping its privileges first.

References

• https://nvd.nist.gov/vuln/detail/CVE-2020-3812
• https://bugs.debian.org/961060
• https://lists.debian.org/debian-lts-announce/2020/06/msg00002.html
• https://usn.ubuntu.com/4556-1/
• https://www.debian.org/security/2020/dsa-4692
• https://www.openwall.com/lists/oss-security/2020/05/19/8