OpenPrinting CUPS: Heap out-of-bounds read in SNMP supply-level polling leaks stack memory to authenticated users

OpenPrinting CUPS has a flaw in its SNMP supply-level polling that allows an attacker to leak up to 176 bytes of memory from the printer server. This leaked data becomes visible to authenticated users when they check printer information, potentially exposing sensitive information.

A network-adjacent attacker can send a crafted SNMP response to trigger an out-of-bounds heap read in the CUPS SNMP backend, leaking stack memory that is converted from UTF-16 to UTF-8 and stored as printer supply descriptions. The leaked data is then exposed to authenticated users via IPP Get-Printer-Attributes responses and the web interface. Pre-condition: SNMP backend enabled and network access to CUPS; impact is information disclosure of stack contents (CWE-125, CWE-200).