[Pkg-net-snmp-devel] Bug#911132: snmpd: Upgrading the snmpd package removes system user named "snmp"

[Ramon Cahenzli]

Package: snmpd
Version: 5.7.3+dfsg-1.7+deb9u1
Severity: normal           
            
Dear Maintainer,

The snmp package appears to remove any system user named "snmp"
whenever it is upgraded.

How to reproduce:

  1. Downgrade your snmpd package (e.g. by removing the package,
     removing the security repository and installing the package
     again from the main repository)

  2. Create a system user called "snmp"

  3. Add the security repository, apt-get update and apt-get upgrade.
     Observe that the snmpd package will be upgraded.
 
  4. Observe that the user "snmp" is gone from the system.

The expected outcome would be that the user "snmp" still exists. 

Ever since the migration to the user "Debian-snmp", admins may be using
users called "snmp" for other purposes than what Debian-snmp is
intended for, so snmpd shouldn't remove these users.


-- System Information:
Debian Release: 9.5
  APT prefers stable-updates
  APT policy: (500, 'stable-updates'), (500, 'stable')
Architecture: amd64 (x86_64)

Kernel: Linux 4.9.0-8-amd64 (SMP w/16 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8),
LANGUAGE=en_US:en (charmap=UTF-8) Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages snmpd depends on:
ii  adduser                3.115
ii  debconf [debconf-2.0]  1.5.61
ii  init-system-helpers    1.48
ii  libc6                  2.24-11+deb9u3
ii  libsnmp-base           5.7.3+dfsg-1.7+deb9u1
ii  libsnmp30              5.7.3+dfsg-1.7+deb9u1
ii  lsb-base               9.20161125

snmpd recommends no packages.

Versions of packages snmpd suggests:
pn  snmptrapd  <none>

-- Configuration Files:
/etc/default/snmpd changed:
export MIBS=
SNMPDRUN=yes
SNMPDOPTS='-LS4d -Lf /dev/null -u snmp -g snmp -I
-smux,mteTrigger,mteTriggerConf -p /run/snmpd.pid'

/etc/snmp/snmpd.conf [Errno 13] Permission denied:
'/etc/snmp/snmpd.conf' /etc/snmp/snmptrapd.conf [Errno 13] Permission
denied: '/etc/snmp/snmptrapd.conf'

-- debconf information:
  snmpd/upgradefrom521: